FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/webrtc-adapter/.eslintrc

@@ -0,0 +1,70 @@
+{
+  "rules": {
+    "array-bracket-spacing": 2,
+    "block-spacing": [2, "never"],
+    "brace-style": [2, "1tbs", {"allowSingleLine": false}],
+    "camelcase": [2, {"properties": "always"}],
+    "curly": 2,
+    "default-case": 2,
+    "dot-notation": 2,
+    "eqeqeq": 2,
+    "id-match": ["error", "^[\x00-\x7F]+$", {
+        "properties": true,
+        "onlyDeclarations": false,
+        "ignoreDestructuring": false
+    }],
+    "indent": [
+        2,
+        2,
+        {"SwitchCase": 1}
+    ],
+    "key-spacing": [2, {"beforeColon": false, "afterColon": true}],
+    "keyword-spacing": 2,
+    "max-len": [2, 80, 2, {"ignoreUrls": true}],
+    "new-cap": [2, {"newIsCapExceptions": [
+        "webkitRTCPeerConnection",
+        "mozRTCPeerConnection"
+    ]}],
+    "no-console": 0,
+    "no-else-return": 2,
+    "no-eval": 2,
+    "no-multi-spaces": 2,
+    "no-multiple-empty-lines": [2, {"max": 2}],
+    "no-shadow": 2,
+    "no-trailing-spaces": 2,
+    "no-unused-expressions": 2,
+    "no-unused-vars": [2, {"args": "none"}],
+    "object-curly-spacing": [2, "never"],
+    "padded-blocks": [2, "never"],
+    "quotes": [
+        2,
+        "single"
+    ],
+    "semi": [
+        2,
+        "always"
+    ],
+    "space-before-blocks": 2,
+    "space-before-function-paren": [2, "never"],
+    "space-unary-ops": 2,
+    "space-infix-ops": 2,
+    "spaced-comment": 2,
+    "valid-typeof": 2
+  },
+  "env": {
+      "browser": true,
+      "es6": true,
+      "node": true
+  },
+  "extends": ["eslint:recommended"],
+  "parserOptions": {
+    "sourceType": "module"
+  },
+  "globals": {
+    "module": true,
+    "require": true,
+    "process": true,
+    "Promise": true,
+    "Map": true
+  }
+}

node_modules/webrtc-adapter/CONTRIBUTING.md

@@ -0,0 +1,15 @@
+WebRTC welcomes patches/pulls for features and bug fixes.
+
+For contributors external to Google, follow the instructions given in the [Google Individual Contributor License Agreement](https://cla.developers.google.com/about/google-individual).
+
+In all cases, contributors must sign a contributor license agreement before a contribution can be accepted. Please complete the agreement for an [individual](https://developers.google.com/open-source/cla/individual) or a [corporation](https://developers.google.com/open-source/cla/corporate) as appropriate.
+
+If you plan to add a significant component or large chunk of code, we recommend you bring this up on the [webrtc-discuss group](https://groups.google.com/forum/#!forum/discuss-webrtc) for a design discussion before writing code.
+
+If appropriate, write a unit test which demonstrates that your code functions as expected. Tests are the best way to ensure that future contributors do not break your code accidentally.
+
+To request a change or addition, you must [submit a pull request](https://help.github.com/categories/collaborating/).
+
+WebRTC developers monitor outstanding pull requests. They may request changes to the pull request before accepting. They will also verify that a CLA has been signed.
+
+The [Developer's Guide](https://bit.ly/webrtcdevguide) for this repo has more detailed information about code style, structure and validation.

node_modules/webrtc-adapter/Gruntfile.js

@@ -0,0 +1,65 @@
+'use strict';
+
+module.exports = function(grunt) {
+  grunt.initConfig({
+    pkg: grunt.file.readJSON('package.json'),
+    babel: {
+      options: {
+        presets: ['@babel/preset-env']
+      },
+      dist: {
+        files: [{
+          expand: 'true',
+          cwd: 'src/js',
+          src: ['*.js', '**/*.js'],
+          dest: 'dist/'
+        }]
+      }
+    },
+    browserify: {
+      adapterGlobalObject: {
+        src: ['./dist/adapter_core5.js'],
+        dest: './out/adapter.js',
+        options: {
+          browserifyOptions: {
+            // Exposes shim methods in a global object to the browser.
+            // The tests require this.
+            standalone: 'adapter'
+          }
+        }
+      },
+      // Use this if you do not want adapter to expose anything to the global
+      // scope.
+      adapterAndNoGlobalObject: {
+        src: ['./dist/adapter_core5.js'],
+        dest: './out/adapter_no_global.js'
+      }
+    },
+    eslint: {
+      options: {
+        overrideConfigFile: '.eslintrc'
+      },
+      target: ['src/**/*.js', 'test/*.js', 'test/unit/*.js', 'test/e2e/*.js']
+    },
+    copy: {
+      build: {
+        dest: 'release/',
+        cwd: 'out',
+        src: '**',
+        nonull: true,
+        expand: true
+      }
+    },
+  });
+
+  grunt.loadNpmTasks('grunt-eslint');
+  grunt.loadNpmTasks('grunt-browserify');
+  grunt.loadNpmTasks('grunt-babel');
+  grunt.loadNpmTasks('grunt-contrib-copy');
+
+  grunt.registerTask('default', ['eslint', 'build']);
+  grunt.registerTask('lint', ['eslint']);
+  grunt.registerTask('build', ['babel', 'browserify']);
+  grunt.registerTask('copyForPublish', ['copy']);
+  grunt.registerTask('downloadBrowser', ['shell:downloadBrowser'])
+};

node_modules/webrtc-adapter/LICENSE.md

@@ -0,0 +1,30 @@
+Copyright (c) 2014, The WebRTC project authors. All rights reserved.
+Copyright (c) 2018, The adapter.js project authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+  * Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+  * Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+  * Neither the name of Google nor the names of its contributors may
+    be used to endorse or promote products derived from this software
+    without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

node_modules/webrtc-adapter/README.md

@@ -0,0 +1,80 @@
+# WebRTC adapter #
+adapter.js is a shim to insulate apps from spec changes and prefix differences in WebRTC. The prefix differences are mostly gone these days but differences in behaviour between browsers remain.
+
+This repository used to be part of the WebRTC organisation on github but moved. We aim to keep the old repository updated with new releases.
+
+## Install ##
+
+#### NPM
+```bash
+npm install webrtc-adapter
+```
+
+#### Bower
+```bash
+bower install webrtc-adapter
+```
+
+## Usage ##
+##### Javascript
+Just import adapter:
+```
+import adapter from 'webrtc-adapter';
+```
+No further action is required. You might want to use adapters browser detection
+which detects which webrtc quirks are required. You can look at
+```
+adapter.browserDetails.browser
+```
+for webrtc engine detection (which will for example detect Opera or the Chromium based Edge as 'chrome') and
+```
+adapter.browserDetails.version
+```
+for the version according to the user-agent string.
+
+##### NPM
+Copy to desired location in your src tree or use a minify/vulcanize tool (node_modules is usually not published with the code).
+See [webrtc/samples repo](https://github.com/webrtc/samples) as an example on how you can do this.
+
+#### Prebuilt releases
+##### Web
+In the [gh-pages branch](https://github.com/webrtcHacks/adapter/tree/gh-pages) prebuilt ready to use files can be downloaded/linked directly.
+Latest version can be found at https://webrtc.github.io/adapter/adapter-latest.js.
+Specific versions can be found at https://webrtc.github.io/adapter/adapter-N.N.N.js, e.g. https://webrtc.github.io/adapter/adapter-1.0.2.js.
+
+##### Bower
+You will find `adapter.js` in `bower_components/webrtc-adapter/`.
+
+##### NPM
+In node_modules/webrtc-adapter/out/ folder you will find 4 files:
+* `adapter.js` - includes all the shims and is visible in the browser under the global `adapter` object (window.adapter).
+* `adapter_no_global.js` - same as `adapter.js` but is not exposed/visible in the browser (you cannot call/interact with the shims in the browser).
+
+Include the file that suits your need in your project.
+
+## Development ##
+Head over to [test/README.md](https://github.com/webrtcHacks/adapter/blob/master/test/README.md) and get started developing.
+
+## Publish a new version ##
+* Go to the adapter repository root directory
+* Make sure your repository is clean, i.e. no untracked files etc. Also check that you are on the master branch and have pulled the latest changes.
+* Depending on the impact of the release, either use `patch`, `minor` or `major` in place of `<version>`. Run `npm version <version> -m 'bump to %s'` and type in your password lots of times (setting up credential caching is probably a good idea).
+* Create and merge the PR if green in the GitHub web ui
+* Go to the releases tab in the GitHub web ui and edit the tag.
+* Add a summary of the recent commits in the tag summary and a link to the diff between the previous and current version in the description, [example](https://github.com/webrtcHacks/adapter/releases/tag/v3.4.1).
+* Go back to your checkout and run `git pull`
+* Run `npm publish` (you need access to the [webrtc-adapter npmjs package](https://www.npmjs.com/package/webrtc-adapter)). For big changes, consider using a [tag version](https://docs.npmjs.com/adding-dist-tags-to-packages) such as `next` and then [change the dist-tag after testing](https://docs.npmjs.com/cli/dist-tag).
+* Done! There should now be a new release published to NPM and the gh-pages branch.
+
+Note: Currently only tested on Linux, not sure about Mac but will definitely not work on Windows.
+
+### Publish a hotfix patch versions
+In some cases it may be necessary to do a patch version while there are significant changes changes on the master branch.
+To make a patch release,
+* checkout the latest git tag using `git checkout tags/vMajor.minor.patch`.
+* checkout a new branch, using a name such as patchrelease-major-minor-patch. 
+* cherry-pick the fixes using `git cherry-pick some-commit-hash`.
+* run `npm version patch`. This will create a new patch version and publish it on github.
+* check out `origin/bumpVersion` branch and publish the new version using `npm publish`.
+* the branch can now safely be deleted. It is not necessary to merge it into the main branch since it only contains cherry-picked commits.
+* after publishing a hotfiix use `npm dist-tag` to ensure latest still points to the highest version.

node_modules/webrtc-adapter/bower.json

@@ -0,0 +1,25 @@
+{
+  "name": "webrtc-adapter",
+  "description": "A shim to insulate apps from WebRTC spec changes and browser prefix differences",
+  "license": "BSD-3-Clause",
+  "main": "./release/adapter.js",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/webrtchacks/adapter.git"
+  },
+  "authors": [
+    "The WebRTC project authors (https://www.webrtc.org/)",
+    "The adapter.js project authors (https://github.com/webrtchacks/adapter/)"
+  ],
+  "moduleType": [
+    "node"
+  ],
+  "ignore": [
+    "test/*"
+  ],
+  "keywords": [
+    "WebRTC",
+    "RTCPeerConnection",
+    "getUserMedia"
+  ]
+}

node_modules/webrtc-adapter/dist/adapter_core.js

@@ -0,0 +1,20 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports["default"] = void 0;
+var _adapter_factory = require("./adapter_factory.js");
+var adapter = (0, _adapter_factory.adapterFactory)({
+  window: typeof window === 'undefined' ? undefined : window
+});
+var _default = exports["default"] = adapter;

node_modules/webrtc-adapter/dist/adapter_core5.js

@@ -0,0 +1,16 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+
+'use strict';
+
+var _adapter_factory = require("./adapter_factory.js");
+var adapter = (0, _adapter_factory.adapterFactory)({
+  window: typeof window === 'undefined' ? undefined : window
+});
+module.exports = adapter; // this is the difference from adapter_core.

node_modules/webrtc-adapter/dist/adapter_factory.js

@@ -0,0 +1,140 @@
+"use strict";
+
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.adapterFactory = adapterFactory;
+var utils = _interopRequireWildcard(require("./utils"));
+var chromeShim = _interopRequireWildcard(require("./chrome/chrome_shim"));
+var firefoxShim = _interopRequireWildcard(require("./firefox/firefox_shim"));
+var safariShim = _interopRequireWildcard(require("./safari/safari_shim"));
+var commonShim = _interopRequireWildcard(require("./common_shim"));
+var sdp = _interopRequireWildcard(require("sdp"));
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+
+// Browser shims.
+
+// Shimming starts here.
+function adapterFactory() {
+  var _ref = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {},
+    window = _ref.window;
+  var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {
+    shimChrome: true,
+    shimFirefox: true,
+    shimSafari: true
+  };
+  // Utils.
+  var logging = utils.log;
+  var browserDetails = utils.detectBrowser(window);
+  var adapter = {
+    browserDetails: browserDetails,
+    commonShim: commonShim,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings,
+    // Expose sdp as a convenience. For production apps include directly.
+    sdp: sdp
+  };
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection || !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      if (browserDetails.version === null) {
+        logging('Chrome shim can not determine version, not shimming.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+
+      // Must be called before shimPeerConnection.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+      chromeShim.shimGetUserMedia(window, browserDetails);
+      chromeShim.shimMediaStream(window, browserDetails);
+      chromeShim.shimPeerConnection(window, browserDetails);
+      chromeShim.shimOnTrack(window, browserDetails);
+      chromeShim.shimAddTrackRemoveTrack(window, browserDetails);
+      chromeShim.shimGetSendersWithDtmf(window, browserDetails);
+      chromeShim.shimSenderReceiverGetStats(window, browserDetails);
+      chromeShim.fixNegotiationNeeded(window, browserDetails);
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimRTCIceCandidateRelayProtocol(window, browserDetails);
+      commonShim.shimConnectionState(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      commonShim.removeExtmapAllowMixed(window, browserDetails);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection || !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+
+      // Must be called before shimPeerConnection.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+      firefoxShim.shimGetUserMedia(window, browserDetails);
+      firefoxShim.shimPeerConnection(window, browserDetails);
+      firefoxShim.shimGetStats(window, browserDetails);
+      firefoxShim.shimOnTrack(window, browserDetails);
+      firefoxShim.shimRemoveStream(window, browserDetails);
+      firefoxShim.shimSenderGetStats(window, browserDetails);
+      firefoxShim.shimReceiverGetStats(window, browserDetails);
+      firefoxShim.shimRTCDataChannel(window, browserDetails);
+      firefoxShim.shimAddTransceiver(window, browserDetails);
+      firefoxShim.shimGetParameters(window, browserDetails);
+      firefoxShim.shimCreateOffer(window, browserDetails);
+      firefoxShim.shimCreateAnswer(window, browserDetails);
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimConnectionState(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+
+      // Must be called before shimCallbackAPI.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+      safariShim.shimRTCIceServerUrls(window, browserDetails);
+      safariShim.shimCreateOfferLegacy(window, browserDetails);
+      safariShim.shimCallbacksAPI(window, browserDetails);
+      safariShim.shimLocalStreamsAPI(window, browserDetails);
+      safariShim.shimRemoteStreamsAPI(window, browserDetails);
+      safariShim.shimTrackEventTransceiver(window, browserDetails);
+      safariShim.shimGetUserMedia(window, browserDetails);
+      safariShim.shimAudioContext(window, browserDetails);
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimRTCIceCandidateRelayProtocol(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      commonShim.removeExtmapAllowMixed(window, browserDetails);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+  return adapter;
+}

node_modules/webrtc-adapter/dist/chrome/chrome_shim.js

@@ -0,0 +1,635 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.fixNegotiationNeeded = fixNegotiationNeeded;
+exports.shimAddTrackRemoveTrack = shimAddTrackRemoveTrack;
+exports.shimAddTrackRemoveTrackWithNative = shimAddTrackRemoveTrackWithNative;
+exports.shimGetSendersWithDtmf = shimGetSendersWithDtmf;
+Object.defineProperty(exports, "shimGetUserMedia", {
+  enumerable: true,
+  get: function get() {
+    return _getusermedia.shimGetUserMedia;
+  }
+});
+exports.shimMediaStream = shimMediaStream;
+exports.shimOnTrack = shimOnTrack;
+exports.shimPeerConnection = shimPeerConnection;
+exports.shimSenderReceiverGetStats = shimSenderReceiverGetStats;
+var utils = _interopRequireWildcard(require("../utils.js"));
+var _getusermedia = require("./getusermedia");
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+function _defineProperty(e, r, t) { return (r = _toPropertyKey(r)) in e ? Object.defineProperty(e, r, { value: t, enumerable: !0, configurable: !0, writable: !0 }) : e[r] = t, e; }
+function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == _typeof(i) ? i : i + ""; }
+function _toPrimitive(t, r) { if ("object" != _typeof(t) || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != _typeof(i)) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+function shimMediaStream(window) {
+  window.MediaStream = window.MediaStream || window.webkitMediaStream;
+}
+function shimOnTrack(window, browserDetails) {
+  if (browserDetails.version > 102) {
+    // Unified plan is supported so no need to do anything.
+    return;
+  }
+  if (_typeof(window) === 'object' && window.RTCPeerConnection && !('ontrack' in window.RTCPeerConnection.prototype)) {
+    Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+      get: function get() {
+        return this._ontrack;
+      },
+      set: function set(f) {
+        if (this._ontrack) {
+          this.removeEventListener('track', this._ontrack);
+        }
+        this.addEventListener('track', this._ontrack = f);
+      },
+      enumerable: true,
+      configurable: true
+    });
+    var origSetRemoteDescription = window.RTCPeerConnection.prototype.setRemoteDescription;
+    window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription() {
+      var _this = this;
+      if (!this._ontrackpoly) {
+        this._ontrackpoly = function (e) {
+          // onaddstream does not fire when a track is added to an existing
+          // stream. But stream.onaddtrack is implemented so we use that.
+          e.stream.addEventListener('addtrack', function (te) {
+            var receiver;
+            if (window.RTCPeerConnection.prototype.getReceivers) {
+              receiver = _this.getReceivers().find(function (r) {
+                return r.track && r.track.id === te.track.id;
+              });
+            } else {
+              receiver = {
+                track: te.track
+              };
+            }
+            var event = new Event('track');
+            event.track = te.track;
+            event.receiver = receiver;
+            event.transceiver = {
+              receiver: receiver
+            };
+            event.streams = [e.stream];
+            _this.dispatchEvent(event);
+          });
+          e.stream.getTracks().forEach(function (track) {
+            var receiver;
+            if (window.RTCPeerConnection.prototype.getReceivers) {
+              receiver = _this.getReceivers().find(function (r) {
+                return r.track && r.track.id === track.id;
+              });
+            } else {
+              receiver = {
+                track: track
+              };
+            }
+            var event = new Event('track');
+            event.track = track;
+            event.receiver = receiver;
+            event.transceiver = {
+              receiver: receiver
+            };
+            event.streams = [e.stream];
+            _this.dispatchEvent(event);
+          });
+        };
+        this.addEventListener('addstream', this._ontrackpoly);
+      }
+      return origSetRemoteDescription.apply(this, arguments);
+    };
+  } else {
+    // even if RTCRtpTransceiver is in window, it is only used and
+    // emitted in unified-plan. Unfortunately this means we need
+    // to unconditionally wrap the event.
+    utils.wrapPeerConnectionEvent(window, 'track', function (e) {
+      if (!e.transceiver) {
+        Object.defineProperty(e, 'transceiver', {
+          value: {
+            receiver: e.receiver
+          }
+        });
+      }
+      return e;
+    });
+  }
+}
+function shimGetSendersWithDtmf(window) {
+  // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+  if (_typeof(window) === 'object' && window.RTCPeerConnection && !('getSenders' in window.RTCPeerConnection.prototype) && 'createDTMFSender' in window.RTCPeerConnection.prototype) {
+    var shimSenderWithDtmf = function shimSenderWithDtmf(pc, track) {
+      return {
+        track: track,
+        get dtmf() {
+          if (this._dtmf === undefined) {
+            if (track.kind === 'audio') {
+              this._dtmf = pc.createDTMFSender(track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        },
+        _pc: pc
+      };
+    };
+
+    // augment addTrack when getSenders is not available.
+    if (!window.RTCPeerConnection.prototype.getSenders) {
+      window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+        this._senders = this._senders || [];
+        return this._senders.slice(); // return a copy of the internal state.
+      };
+      var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
+        var sender = origAddTrack.apply(this, arguments);
+        if (!sender) {
+          sender = shimSenderWithDtmf(this, track);
+          this._senders.push(sender);
+        }
+        return sender;
+      };
+      var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+      window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
+        origRemoveTrack.apply(this, arguments);
+        var idx = this._senders.indexOf(sender);
+        if (idx !== -1) {
+          this._senders.splice(idx, 1);
+        }
+      };
+    }
+    var origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+      var _this2 = this;
+      this._senders = this._senders || [];
+      origAddStream.apply(this, [stream]);
+      stream.getTracks().forEach(function (track) {
+        _this2._senders.push(shimSenderWithDtmf(_this2, track));
+      });
+    };
+    var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
+      var _this3 = this;
+      this._senders = this._senders || [];
+      origRemoveStream.apply(this, [stream]);
+      stream.getTracks().forEach(function (track) {
+        var sender = _this3._senders.find(function (s) {
+          return s.track === track;
+        });
+        if (sender) {
+          // remove sender
+          _this3._senders.splice(_this3._senders.indexOf(sender), 1);
+        }
+      });
+    };
+  } else if (_typeof(window) === 'object' && window.RTCPeerConnection && 'getSenders' in window.RTCPeerConnection.prototype && 'createDTMFSender' in window.RTCPeerConnection.prototype && window.RTCRtpSender && !('dtmf' in window.RTCRtpSender.prototype)) {
+    var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+    window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+      var _this4 = this;
+      var senders = origGetSenders.apply(this, []);
+      senders.forEach(function (sender) {
+        return sender._pc = _this4;
+      });
+      return senders;
+    };
+    Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+      get: function get() {
+        if (this._dtmf === undefined) {
+          if (this.track.kind === 'audio') {
+            this._dtmf = this._pc.createDTMFSender(this.track);
+          } else {
+            this._dtmf = null;
+          }
+        }
+        return this._dtmf;
+      }
+    });
+  }
+}
+function shimSenderReceiverGetStats(window, browserDetails) {
+  if (browserDetails.version >= 67) {
+    return;
+  }
+  if (!(_typeof(window) === 'object' && window.RTCPeerConnection && window.RTCRtpSender && window.RTCRtpReceiver)) {
+    return;
+  }
+
+  // shim sender stats.
+  if (!('getStats' in window.RTCRtpSender.prototype)) {
+    var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+    if (origGetSenders) {
+      window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+        var _this5 = this;
+        var senders = origGetSenders.apply(this, []);
+        senders.forEach(function (sender) {
+          return sender._pc = _this5;
+        });
+        return senders;
+      };
+    }
+    var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+    if (origAddTrack) {
+      window.RTCPeerConnection.prototype.addTrack = function addTrack() {
+        var sender = origAddTrack.apply(this, arguments);
+        sender._pc = this;
+        return sender;
+      };
+    }
+    window.RTCRtpSender.prototype.getStats = function getStats() {
+      var sender = this;
+      return this._pc.getStats().then(function (result) {
+        return (
+          /* Note: this will include stats of all senders that
+           *   send a track with the same id as sender.track as
+           *   it is not possible to identify the RTCRtpSender.
+           */
+          utils.filterStats(result, sender.track, true)
+        );
+      });
+    };
+  }
+
+  // shim receiver stats.
+  if (!('getStats' in window.RTCRtpReceiver.prototype)) {
+    var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
+    if (origGetReceivers) {
+      window.RTCPeerConnection.prototype.getReceivers = function getReceivers() {
+        var _this6 = this;
+        var receivers = origGetReceivers.apply(this, []);
+        receivers.forEach(function (receiver) {
+          return receiver._pc = _this6;
+        });
+        return receivers;
+      };
+    }
+    utils.wrapPeerConnectionEvent(window, 'track', function (e) {
+      e.receiver._pc = e.srcElement;
+      return e;
+    });
+    window.RTCRtpReceiver.prototype.getStats = function getStats() {
+      var receiver = this;
+      return this._pc.getStats().then(function (result) {
+        return utils.filterStats(result, receiver.track, false);
+      });
+    };
+  }
+  if (!('getStats' in window.RTCRtpSender.prototype && 'getStats' in window.RTCRtpReceiver.prototype)) {
+    return;
+  }
+
+  // shim RTCPeerConnection.getStats(track).
+  var origGetStats = window.RTCPeerConnection.prototype.getStats;
+  window.RTCPeerConnection.prototype.getStats = function getStats() {
+    if (arguments.length > 0 && arguments[0] instanceof window.MediaStreamTrack) {
+      var track = arguments[0];
+      var sender;
+      var receiver;
+      var err;
+      this.getSenders().forEach(function (s) {
+        if (s.track === track) {
+          if (sender) {
+            err = true;
+          } else {
+            sender = s;
+          }
+        }
+      });
+      this.getReceivers().forEach(function (r) {
+        if (r.track === track) {
+          if (receiver) {
+            err = true;
+          } else {
+            receiver = r;
+          }
+        }
+        return r.track === track;
+      });
+      if (err || sender && receiver) {
+        return Promise.reject(new DOMException('There are more than one sender or receiver for the track.', 'InvalidAccessError'));
+      } else if (sender) {
+        return sender.getStats();
+      } else if (receiver) {
+        return receiver.getStats();
+      }
+      return Promise.reject(new DOMException('There is no sender or receiver for the track.', 'InvalidAccessError'));
+    }
+    return origGetStats.apply(this, arguments);
+  };
+}
+function shimAddTrackRemoveTrackWithNative(window) {
+  // shim addTrack/removeTrack with native variants in order to make
+  // the interactions with legacy getLocalStreams behave as in other browsers.
+  // Keeps a mapping stream.id => [stream, rtpsenders...]
+  window.RTCPeerConnection.prototype.getLocalStreams = function getLocalStreams() {
+    var _this7 = this;
+    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+    return Object.keys(this._shimmedLocalStreams).map(function (streamId) {
+      return _this7._shimmedLocalStreams[streamId][0];
+    });
+  };
+  var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+  window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
+    if (!stream) {
+      return origAddTrack.apply(this, arguments);
+    }
+    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+    var sender = origAddTrack.apply(this, arguments);
+    if (!this._shimmedLocalStreams[stream.id]) {
+      this._shimmedLocalStreams[stream.id] = [stream, sender];
+    } else if (this._shimmedLocalStreams[stream.id].indexOf(sender) === -1) {
+      this._shimmedLocalStreams[stream.id].push(sender);
+    }
+    return sender;
+  };
+  var origAddStream = window.RTCPeerConnection.prototype.addStream;
+  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+    var _this8 = this;
+    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+    stream.getTracks().forEach(function (track) {
+      var alreadyExists = _this8.getSenders().find(function (s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.', 'InvalidAccessError');
+      }
+    });
+    var existingSenders = this.getSenders();
+    origAddStream.apply(this, arguments);
+    var newSenders = this.getSenders().filter(function (newSender) {
+      return existingSenders.indexOf(newSender) === -1;
+    });
+    this._shimmedLocalStreams[stream.id] = [stream].concat(newSenders);
+  };
+  var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+  window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
+    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+    delete this._shimmedLocalStreams[stream.id];
+    return origRemoveStream.apply(this, arguments);
+  };
+  var origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+  window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
+    var _this9 = this;
+    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+    if (sender) {
+      Object.keys(this._shimmedLocalStreams).forEach(function (streamId) {
+        var idx = _this9._shimmedLocalStreams[streamId].indexOf(sender);
+        if (idx !== -1) {
+          _this9._shimmedLocalStreams[streamId].splice(idx, 1);
+        }
+        if (_this9._shimmedLocalStreams[streamId].length === 1) {
+          delete _this9._shimmedLocalStreams[streamId];
+        }
+      });
+    }
+    return origRemoveTrack.apply(this, arguments);
+  };
+}
+function shimAddTrackRemoveTrack(window, browserDetails) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  // shim addTrack and removeTrack.
+  if (window.RTCPeerConnection.prototype.addTrack && browserDetails.version >= 65) {
+    return shimAddTrackRemoveTrackWithNative(window);
+  }
+
+  // also shim pc.getLocalStreams when addTrack is shimmed
+  // to return the original streams.
+  var origGetLocalStreams = window.RTCPeerConnection.prototype.getLocalStreams;
+  window.RTCPeerConnection.prototype.getLocalStreams = function getLocalStreams() {
+    var _this0 = this;
+    var nativeStreams = origGetLocalStreams.apply(this);
+    this._reverseStreams = this._reverseStreams || {};
+    return nativeStreams.map(function (stream) {
+      return _this0._reverseStreams[stream.id];
+    });
+  };
+  var origAddStream = window.RTCPeerConnection.prototype.addStream;
+  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+    var _this1 = this;
+    this._streams = this._streams || {};
+    this._reverseStreams = this._reverseStreams || {};
+    stream.getTracks().forEach(function (track) {
+      var alreadyExists = _this1.getSenders().find(function (s) {
+        return s.track === track;
+      });
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.', 'InvalidAccessError');
+      }
+    });
+    // Add identity mapping for consistency with addTrack.
+    // Unless this is being used with a stream from addTrack.
+    if (!this._reverseStreams[stream.id]) {
+      var newStream = new window.MediaStream(stream.getTracks());
+      this._streams[stream.id] = newStream;
+      this._reverseStreams[newStream.id] = stream;
+      stream = newStream;
+    }
+    origAddStream.apply(this, [stream]);
+  };
+  var origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+  window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
+    this._streams = this._streams || {};
+    this._reverseStreams = this._reverseStreams || {};
+    origRemoveStream.apply(this, [this._streams[stream.id] || stream]);
+    delete this._reverseStreams[this._streams[stream.id] ? this._streams[stream.id].id : stream.id];
+    delete this._streams[stream.id];
+  };
+  window.RTCPeerConnection.prototype.addTrack = function addTrack(track, stream) {
+    var _this10 = this;
+    if (this.signalingState === 'closed') {
+      throw new DOMException('The RTCPeerConnection\'s signalingState is \'closed\'.', 'InvalidStateError');
+    }
+    var streams = [].slice.call(arguments, 1);
+    if (streams.length !== 1 || !streams[0].getTracks().find(function (t) {
+      return t === track;
+    })) {
+      // this is not fully correct but all we can manage without
+      // [[associated MediaStreams]] internal slot.
+      throw new DOMException('The adapter.js addTrack polyfill only supports a single ' + ' stream which is associated with the specified track.', 'NotSupportedError');
+    }
+    var alreadyExists = this.getSenders().find(function (s) {
+      return s.track === track;
+    });
+    if (alreadyExists) {
+      throw new DOMException('Track already exists.', 'InvalidAccessError');
+    }
+    this._streams = this._streams || {};
+    this._reverseStreams = this._reverseStreams || {};
+    var oldStream = this._streams[stream.id];
+    if (oldStream) {
+      // this is using odd Chrome behaviour, use with caution:
+      // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+      // Note: we rely on the high-level addTrack/dtmf shim to
+      // create the sender with a dtmf sender.
+      oldStream.addTrack(track);
+
+      // Trigger ONN async.
+      Promise.resolve().then(function () {
+        _this10.dispatchEvent(new Event('negotiationneeded'));
+      });
+    } else {
+      var newStream = new window.MediaStream([track]);
+      this._streams[stream.id] = newStream;
+      this._reverseStreams[newStream.id] = stream;
+      this.addStream(newStream);
+    }
+    return this.getSenders().find(function (s) {
+      return s.track === track;
+    });
+  };
+
+  // replace the internal stream id with the external one and
+  // vice versa.
+  function replaceInternalStreamId(pc, description) {
+    var sdp = description.sdp;
+    Object.keys(pc._reverseStreams || []).forEach(function (internalId) {
+      var externalStream = pc._reverseStreams[internalId];
+      var internalStream = pc._streams[externalStream.id];
+      sdp = sdp.replace(new RegExp(internalStream.id, 'g'), externalStream.id);
+    });
+    return new RTCSessionDescription({
+      type: description.type,
+      sdp: sdp
+    });
+  }
+  function replaceExternalStreamId(pc, description) {
+    var sdp = description.sdp;
+    Object.keys(pc._reverseStreams || []).forEach(function (internalId) {
+      var externalStream = pc._reverseStreams[internalId];
+      var internalStream = pc._streams[externalStream.id];
+      sdp = sdp.replace(new RegExp(externalStream.id, 'g'), internalStream.id);
+    });
+    return new RTCSessionDescription({
+      type: description.type,
+      sdp: sdp
+    });
+  }
+  ['createOffer', 'createAnswer'].forEach(function (method) {
+    var nativeMethod = window.RTCPeerConnection.prototype[method];
+    var methodObj = _defineProperty({}, method, function () {
+      var _this11 = this;
+      var args = arguments;
+      var isLegacyCall = arguments.length && typeof arguments[0] === 'function';
+      if (isLegacyCall) {
+        return nativeMethod.apply(this, [function (description) {
+          var desc = replaceInternalStreamId(_this11, description);
+          args[0].apply(null, [desc]);
+        }, function (err) {
+          if (args[1]) {
+            args[1].apply(null, err);
+          }
+        }, arguments[2]]);
+      }
+      return nativeMethod.apply(this, arguments).then(function (description) {
+        return replaceInternalStreamId(_this11, description);
+      });
+    });
+    window.RTCPeerConnection.prototype[method] = methodObj[method];
+  });
+  var origSetLocalDescription = window.RTCPeerConnection.prototype.setLocalDescription;
+  window.RTCPeerConnection.prototype.setLocalDescription = function setLocalDescription() {
+    if (!arguments.length || !arguments[0].type) {
+      return origSetLocalDescription.apply(this, arguments);
+    }
+    arguments[0] = replaceExternalStreamId(this, arguments[0]);
+    return origSetLocalDescription.apply(this, arguments);
+  };
+
+  // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+  var origLocalDescription = Object.getOwnPropertyDescriptor(window.RTCPeerConnection.prototype, 'localDescription');
+  Object.defineProperty(window.RTCPeerConnection.prototype, 'localDescription', {
+    get: function get() {
+      var description = origLocalDescription.get.apply(this);
+      if (description.type === '') {
+        return description;
+      }
+      return replaceInternalStreamId(this, description);
+    }
+  });
+  window.RTCPeerConnection.prototype.removeTrack = function removeTrack(sender) {
+    var _this12 = this;
+    if (this.signalingState === 'closed') {
+      throw new DOMException('The RTCPeerConnection\'s signalingState is \'closed\'.', 'InvalidStateError');
+    }
+    // We can not yet check for sender instanceof RTCRtpSender
+    // since we shim RTPSender. So we check if sender._pc is set.
+    if (!sender._pc) {
+      throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' + 'does not implement interface RTCRtpSender.', 'TypeError');
+    }
+    var isLocal = sender._pc === this;
+    if (!isLocal) {
+      throw new DOMException('Sender was not created by this connection.', 'InvalidAccessError');
+    }
+
+    // Search for the native stream the senders track belongs to.
+    this._streams = this._streams || {};
+    var stream;
+    Object.keys(this._streams).forEach(function (streamid) {
+      var hasTrack = _this12._streams[streamid].getTracks().find(function (track) {
+        return sender.track === track;
+      });
+      if (hasTrack) {
+        stream = _this12._streams[streamid];
+      }
+    });
+    if (stream) {
+      if (stream.getTracks().length === 1) {
+        // if this is the last track of the stream, remove the stream. This
+        // takes care of any shimmed _senders.
+        this.removeStream(this._reverseStreams[stream.id]);
+      } else {
+        // relying on the same odd chrome behaviour as above.
+        stream.removeTrack(sender.track);
+      }
+      this.dispatchEvent(new Event('negotiationneeded'));
+    }
+  };
+}
+function shimPeerConnection(window, browserDetails) {
+  if (!window.RTCPeerConnection && window.webkitRTCPeerConnection) {
+    // very basic support for old versions.
+    window.RTCPeerConnection = window.webkitRTCPeerConnection;
+  }
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+
+  // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+  if (browserDetails.version < 53) {
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate'].forEach(function (method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      var methodObj = _defineProperty({}, method, function () {
+        arguments[0] = new (method === 'addIceCandidate' ? window.RTCIceCandidate : window.RTCSessionDescription)(arguments[0]);
+        return nativeMethod.apply(this, arguments);
+      });
+      window.RTCPeerConnection.prototype[method] = methodObj[method];
+    });
+  }
+}
+
+// Attempt to fix ONN in plan-b mode.
+function fixNegotiationNeeded(window, browserDetails) {
+  if (browserDetails.version > 102) {
+    // Plan-B is no longer supported.
+    return;
+  }
+  utils.wrapPeerConnectionEvent(window, 'negotiationneeded', function (e) {
+    var pc = e.target;
+    if (browserDetails.version < 72 || pc.getConfiguration && pc.getConfiguration().sdpSemantics === 'plan-b') {
+      if (pc.signalingState !== 'stable') {
+        return;
+      }
+    }
+    return e;
+  });
+}

node_modules/webrtc-adapter/dist/chrome/getusermedia.js

@@ -0,0 +1,197 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.shimGetUserMedia = shimGetUserMedia;
+var utils = _interopRequireWildcard(require("../utils.js"));
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+var logging = utils.log;
+function shimGetUserMedia(window, browserDetails) {
+  var navigator = window && window.navigator;
+  if (!navigator.mediaDevices) {
+    return;
+  }
+  var constraintsToChrome_ = function constraintsToChrome_(c) {
+    if (_typeof(c) !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    var cc = {};
+    Object.keys(c).forEach(function (key) {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      var r = _typeof(c[key]) === 'object' ? c[key] : {
+        ideal: c[key]
+      };
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      var oldname_ = function oldname_(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return name === 'deviceId' ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        var oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(function (mix) {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+  var shimConstraints_ = function shimConstraints_(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && _typeof(constraints.audio) === 'object') {
+      var remap = function remap(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && _typeof(constraints.video) === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      var face = constraints.video.facingMode;
+      face = face && (_typeof(face) === 'object' ? face : {
+        ideal: face
+      });
+      var getSupportedFacingModeLies = browserDetails.version < 66;
+      if (face && (face.exact === 'user' || face.exact === 'environment' || face.ideal === 'user' || face.ideal === 'environment') && !(navigator.mediaDevices.getSupportedConstraints && navigator.mediaDevices.getSupportedConstraints().facingMode && !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        var matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices().then(function (devices) {
+            devices = devices.filter(function (d) {
+              return d.kind === 'videoinput';
+            });
+            var dev = devices.find(function (d) {
+              return matches.some(function (match) {
+                return d.label.toLowerCase().includes(match);
+              });
+            });
+            if (!dev && devices.length && matches.includes('back')) {
+              dev = devices[devices.length - 1]; // more likely the back cam
+            }
+            if (dev) {
+              constraints.video.deviceId = face.exact ? {
+                exact: dev.deviceId
+              } : {
+                ideal: dev.deviceId
+              };
+            }
+            constraints.video = constraintsToChrome_(constraints.video);
+            logging('chrome: ' + JSON.stringify(constraints));
+            return func(constraints);
+          });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+  var shimError_ = function shimError_(e) {
+    if (browserDetails.version >= 64) {
+      return e;
+    }
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        PermissionDismissedError: 'NotAllowedError',
+        InvalidStateError: 'NotAllowedError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotAllowedError',
+        MediaDeviceKillSwitchOn: 'NotAllowedError',
+        TabCaptureError: 'AbortError',
+        ScreenCaptureError: 'AbortError',
+        DeviceCaptureError: 'AbortError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraint || e.constraintName,
+      toString: function toString() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+  var getUserMedia_ = function getUserMedia_(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, function (c) {
+      navigator.webkitGetUserMedia(c, onSuccess, function (e) {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+  navigator.getUserMedia = getUserMedia_.bind(navigator);
+
+  // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+  // function which returns a Promise, it does not accept spec-style
+  // constraints.
+  if (navigator.mediaDevices.getUserMedia) {
+    var origGetUserMedia = navigator.mediaDevices.getUserMedia.bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function (cs) {
+      return shimConstraints_(cs, function (c) {
+        return origGetUserMedia(c).then(function (stream) {
+          if (c.audio && !stream.getAudioTracks().length || c.video && !stream.getVideoTracks().length) {
+            stream.getTracks().forEach(function (track) {
+              track.stop();
+            });
+            throw new DOMException('', 'NotFoundError');
+          }
+          return stream;
+        }, function (e) {
+          return Promise.reject(shimError_(e));
+        });
+      });
+    };
+  }
+}

node_modules/webrtc-adapter/dist/common_shim.js

@@ -0,0 +1,441 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.removeExtmapAllowMixed = removeExtmapAllowMixed;
+exports.shimAddIceCandidateNullOrEmpty = shimAddIceCandidateNullOrEmpty;
+exports.shimConnectionState = shimConnectionState;
+exports.shimMaxMessageSize = shimMaxMessageSize;
+exports.shimParameterlessSetLocalDescription = shimParameterlessSetLocalDescription;
+exports.shimRTCIceCandidate = shimRTCIceCandidate;
+exports.shimRTCIceCandidateRelayProtocol = shimRTCIceCandidateRelayProtocol;
+exports.shimSendThrowTypeError = shimSendThrowTypeError;
+var _sdp = _interopRequireDefault(require("sdp"));
+var utils = _interopRequireWildcard(require("./utils"));
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { "default": e }; }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+function shimRTCIceCandidate(window) {
+  // foundation is arbitrarily chosen as an indicator for full support for
+  // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+  if (!window.RTCIceCandidate || window.RTCIceCandidate && 'foundation' in window.RTCIceCandidate.prototype) {
+    return;
+  }
+  var NativeRTCIceCandidate = window.RTCIceCandidate;
+  window.RTCIceCandidate = function RTCIceCandidate(args) {
+    // Remove the a= which shouldn't be part of the candidate string.
+    if (_typeof(args) === 'object' && args.candidate && args.candidate.indexOf('a=') === 0) {
+      args = JSON.parse(JSON.stringify(args));
+      args.candidate = args.candidate.substring(2);
+    }
+    if (args.candidate && args.candidate.length) {
+      // Augment the native candidate with the parsed fields.
+      var nativeCandidate = new NativeRTCIceCandidate(args);
+      var parsedCandidate = _sdp["default"].parseCandidate(args.candidate);
+      for (var key in parsedCandidate) {
+        if (!(key in nativeCandidate)) {
+          Object.defineProperty(nativeCandidate, key, {
+            value: parsedCandidate[key]
+          });
+        }
+      }
+
+      // Override serializer to not serialize the extra attributes.
+      nativeCandidate.toJSON = function toJSON() {
+        return {
+          candidate: nativeCandidate.candidate,
+          sdpMid: nativeCandidate.sdpMid,
+          sdpMLineIndex: nativeCandidate.sdpMLineIndex,
+          usernameFragment: nativeCandidate.usernameFragment
+        };
+      };
+      return nativeCandidate;
+    }
+    return new NativeRTCIceCandidate(args);
+  };
+  window.RTCIceCandidate.prototype = NativeRTCIceCandidate.prototype;
+
+  // Hook up the augmented candidate in onicecandidate and
+  // addEventListener('icecandidate', ...)
+  utils.wrapPeerConnectionEvent(window, 'icecandidate', function (e) {
+    if (e.candidate) {
+      Object.defineProperty(e, 'candidate', {
+        value: new window.RTCIceCandidate(e.candidate),
+        writable: 'false'
+      });
+    }
+    return e;
+  });
+}
+function shimRTCIceCandidateRelayProtocol(window) {
+  if (!window.RTCIceCandidate || window.RTCIceCandidate && 'relayProtocol' in window.RTCIceCandidate.prototype) {
+    return;
+  }
+
+  // Hook up the augmented candidate in onicecandidate and
+  // addEventListener('icecandidate', ...)
+  utils.wrapPeerConnectionEvent(window, 'icecandidate', function (e) {
+    if (e.candidate) {
+      var parsedCandidate = _sdp["default"].parseCandidate(e.candidate.candidate);
+      if (parsedCandidate.type === 'relay') {
+        // This is a libwebrtc-specific mapping of local type preference
+        // to relayProtocol.
+        e.candidate.relayProtocol = {
+          0: 'tls',
+          1: 'tcp',
+          2: 'udp'
+        }[parsedCandidate.priority >> 24];
+      }
+    }
+    return e;
+  });
+}
+function shimMaxMessageSize(window, browserDetails) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  if (!('sctp' in window.RTCPeerConnection.prototype)) {
+    Object.defineProperty(window.RTCPeerConnection.prototype, 'sctp', {
+      get: function get() {
+        return typeof this._sctp === 'undefined' ? null : this._sctp;
+      }
+    });
+  }
+  var sctpInDescription = function sctpInDescription(description) {
+    if (!description || !description.sdp) {
+      return false;
+    }
+    var sections = _sdp["default"].splitSections(description.sdp);
+    sections.shift();
+    return sections.some(function (mediaSection) {
+      var mLine = _sdp["default"].parseMLine(mediaSection);
+      return mLine && mLine.kind === 'application' && mLine.protocol.indexOf('SCTP') !== -1;
+    });
+  };
+  var getRemoteFirefoxVersion = function getRemoteFirefoxVersion(description) {
+    // TODO: Is there a better solution for detecting Firefox?
+    var match = description.sdp.match(/mozilla...THIS_IS_SDPARTA-(\d+)/);
+    if (match === null || match.length < 2) {
+      return -1;
+    }
+    var version = parseInt(match[1], 10);
+    // Test for NaN (yes, this is ugly)
+    return version !== version ? -1 : version;
+  };
+  var getCanSendMaxMessageSize = function getCanSendMaxMessageSize(remoteIsFirefox) {
+    // Every implementation we know can send at least 64 KiB.
+    // Note: Although Chrome is technically able to send up to 256 KiB, the
+    //       data does not reach the other peer reliably.
+    //       See: https://bugs.chromium.org/p/webrtc/issues/detail?id=8419
+    var canSendMaxMessageSize = 65536;
+    if (browserDetails.browser === 'firefox') {
+      if (browserDetails.version < 57) {
+        if (remoteIsFirefox === -1) {
+          // FF < 57 will send in 16 KiB chunks using the deprecated PPID
+          // fragmentation.
+          canSendMaxMessageSize = 16384;
+        } else {
+          // However, other FF (and RAWRTC) can reassemble PPID-fragmented
+          // messages. Thus, supporting ~2 GiB when sending.
+          canSendMaxMessageSize = 2147483637;
+        }
+      } else if (browserDetails.version < 60) {
+        // Currently, all FF >= 57 will reset the remote maximum message size
+        // to the default value when a data channel is created at a later
+        // stage. :(
+        // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
+        canSendMaxMessageSize = browserDetails.version === 57 ? 65535 : 65536;
+      } else {
+        // FF >= 60 supports sending ~2 GiB
+        canSendMaxMessageSize = 2147483637;
+      }
+    }
+    return canSendMaxMessageSize;
+  };
+  var getMaxMessageSize = function getMaxMessageSize(description, remoteIsFirefox) {
+    // Note: 65536 bytes is the default value from the SDP spec. Also,
+    //       every implementation we know supports receiving 65536 bytes.
+    var maxMessageSize = 65536;
+
+    // FF 57 has a slightly incorrect default remote max message size, so
+    // we need to adjust it here to avoid a failure when sending.
+    // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1425697
+    if (browserDetails.browser === 'firefox' && browserDetails.version === 57) {
+      maxMessageSize = 65535;
+    }
+    var match = _sdp["default"].matchPrefix(description.sdp, 'a=max-message-size:');
+    if (match.length > 0) {
+      maxMessageSize = parseInt(match[0].substring(19), 10);
+    } else if (browserDetails.browser === 'firefox' && remoteIsFirefox !== -1) {
+      // If the maximum message size is not present in the remote SDP and
+      // both local and remote are Firefox, the remote peer can receive
+      // ~2 GiB.
+      maxMessageSize = 2147483637;
+    }
+    return maxMessageSize;
+  };
+  var origSetRemoteDescription = window.RTCPeerConnection.prototype.setRemoteDescription;
+  window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription() {
+    this._sctp = null;
+    // Chrome decided to not expose .sctp in plan-b mode.
+    // As usual, adapter.js has to do an 'ugly worakaround'
+    // to cover up the mess.
+    if (browserDetails.browser === 'chrome' && browserDetails.version >= 76) {
+      var _this$getConfiguratio = this.getConfiguration(),
+        sdpSemantics = _this$getConfiguratio.sdpSemantics;
+      if (sdpSemantics === 'plan-b') {
+        Object.defineProperty(this, 'sctp', {
+          get: function get() {
+            return typeof this._sctp === 'undefined' ? null : this._sctp;
+          },
+          enumerable: true,
+          configurable: true
+        });
+      }
+    }
+    if (sctpInDescription(arguments[0])) {
+      // Check if the remote is FF.
+      var isFirefox = getRemoteFirefoxVersion(arguments[0]);
+
+      // Get the maximum message size the local peer is capable of sending
+      var canSendMMS = getCanSendMaxMessageSize(isFirefox);
+
+      // Get the maximum message size of the remote peer.
+      var remoteMMS = getMaxMessageSize(arguments[0], isFirefox);
+
+      // Determine final maximum message size
+      var maxMessageSize;
+      if (canSendMMS === 0 && remoteMMS === 0) {
+        maxMessageSize = Number.POSITIVE_INFINITY;
+      } else if (canSendMMS === 0 || remoteMMS === 0) {
+        maxMessageSize = Math.max(canSendMMS, remoteMMS);
+      } else {
+        maxMessageSize = Math.min(canSendMMS, remoteMMS);
+      }
+
+      // Create a dummy RTCSctpTransport object and the 'maxMessageSize'
+      // attribute.
+      var sctp = {};
+      Object.defineProperty(sctp, 'maxMessageSize', {
+        get: function get() {
+          return maxMessageSize;
+        }
+      });
+      this._sctp = sctp;
+    }
+    return origSetRemoteDescription.apply(this, arguments);
+  };
+}
+function shimSendThrowTypeError(window, browserDetails) {
+  if (!(window.RTCPeerConnection && 'createDataChannel' in window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  if (browserDetails.browser === 'chrome' && browserDetails.version > 149) {
+    // Fixed by https://issues.chromium.org/issues/490588131
+    return;
+  }
+
+  // Note: Although Firefox >= 57 has a native implementation, the maximum
+  //       message size can be reset for all data channels at a later stage.
+  //       See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
+  if (browserDetails.browser === 'firefox' && browserDetails.version > 60) {
+    return;
+  }
+  function wrapDcSend(dc, pc) {
+    var origDataChannelSend = dc.send;
+    dc.send = function send() {
+      var data = arguments[0];
+      var length = data.length || data.size || data.byteLength;
+      if (dc.readyState === 'open' && pc.sctp && length > pc.sctp.maxMessageSize) {
+        throw new TypeError('Message too large (can send a maximum of ' + pc.sctp.maxMessageSize + ' bytes)');
+      }
+      return origDataChannelSend.apply(dc, arguments);
+    };
+  }
+  var origCreateDataChannel = window.RTCPeerConnection.prototype.createDataChannel;
+  window.RTCPeerConnection.prototype.createDataChannel = function createDataChannel() {
+    var dataChannel = origCreateDataChannel.apply(this, arguments);
+    wrapDcSend(dataChannel, this);
+    return dataChannel;
+  };
+  utils.wrapPeerConnectionEvent(window, 'datachannel', function (e) {
+    wrapDcSend(e.channel, e.target);
+    return e;
+  });
+}
+
+/* shims RTCConnectionState by pretending it is the same as iceConnectionState.
+ * See https://bugs.chromium.org/p/webrtc/issues/detail?id=6145#c12
+ * for why this is a valid hack in Chrome. In Firefox it is slightly incorrect
+ * since DTLS failures would be hidden. See
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=1265827
+ * for the Firefox tracking bug.
+ */
+function shimConnectionState(window) {
+  if (!window.RTCPeerConnection || 'connectionState' in window.RTCPeerConnection.prototype) {
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  Object.defineProperty(proto, 'connectionState', {
+    get: function get() {
+      return {
+        completed: 'connected',
+        checking: 'connecting'
+      }[this.iceConnectionState] || this.iceConnectionState;
+    },
+    enumerable: true,
+    configurable: true
+  });
+  Object.defineProperty(proto, 'onconnectionstatechange', {
+    get: function get() {
+      return this._onconnectionstatechange || null;
+    },
+    set: function set(cb) {
+      if (this._onconnectionstatechange) {
+        this.removeEventListener('connectionstatechange', this._onconnectionstatechange);
+        delete this._onconnectionstatechange;
+      }
+      if (cb) {
+        this.addEventListener('connectionstatechange', this._onconnectionstatechange = cb);
+      }
+    },
+    enumerable: true,
+    configurable: true
+  });
+  ['setLocalDescription', 'setRemoteDescription'].forEach(function (method) {
+    var origMethod = proto[method];
+    proto[method] = function () {
+      if (!this._connectionstatechangepoly) {
+        this._connectionstatechangepoly = function (e) {
+          var pc = e.target;
+          if (pc._lastConnectionState !== pc.connectionState) {
+            pc._lastConnectionState = pc.connectionState;
+            var newEvent = new Event('connectionstatechange', e);
+            pc.dispatchEvent(newEvent);
+          }
+          return e;
+        };
+        this.addEventListener('iceconnectionstatechange', this._connectionstatechangepoly);
+      }
+      return origMethod.apply(this, arguments);
+    };
+  });
+}
+function removeExtmapAllowMixed(window, browserDetails) {
+  /* remove a=extmap-allow-mixed for webrtc.org < M71 */
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  if (browserDetails.browser === 'chrome' && browserDetails.version >= 71) {
+    return;
+  }
+  if (browserDetails.browser === 'safari' && browserDetails._safariVersion >= 13.1) {
+    return;
+  }
+  var nativeSRD = window.RTCPeerConnection.prototype.setRemoteDescription;
+  window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription(desc) {
+    if (desc && desc.sdp && desc.sdp.indexOf('\na=extmap-allow-mixed') !== -1) {
+      var sdp = desc.sdp.split('\n').filter(function (line) {
+        return line.trim() !== 'a=extmap-allow-mixed';
+      }).join('\n');
+      // Safari enforces read-only-ness of RTCSessionDescription fields.
+      if (window.RTCSessionDescription && desc instanceof window.RTCSessionDescription) {
+        arguments[0] = new window.RTCSessionDescription({
+          type: desc.type,
+          sdp: sdp
+        });
+      } else {
+        desc.sdp = sdp;
+      }
+    }
+    return nativeSRD.apply(this, arguments);
+  };
+}
+function shimAddIceCandidateNullOrEmpty(window, browserDetails) {
+  // Support for addIceCandidate(null or undefined)
+  // as well as addIceCandidate({candidate: "", ...})
+  // https://bugs.chromium.org/p/chromium/issues/detail?id=978582
+  // Note: must be called before other polyfills which change the signature.
+  if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  var nativeAddIceCandidate = window.RTCPeerConnection.prototype.addIceCandidate;
+  if (!nativeAddIceCandidate || nativeAddIceCandidate.length === 0) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.addIceCandidate = function addIceCandidate() {
+    if (!arguments[0]) {
+      if (arguments[1]) {
+        arguments[1].apply(null);
+      }
+      return Promise.resolve();
+    }
+    // Firefox 68+ emits and processes {candidate: "", ...}, ignore
+    // in older versions.
+    // Native support for ignoring exists for Chrome M77+.
+    // Safari ignores as well, exact version unknown but works in the same
+    // version that also ignores addIceCandidate(null).
+    if ((browserDetails.browser === 'chrome' && browserDetails.version < 78 || browserDetails.browser === 'firefox' && browserDetails.version < 68 || browserDetails.browser === 'safari') && arguments[0] && arguments[0].candidate === '') {
+      return Promise.resolve();
+    }
+    return nativeAddIceCandidate.apply(this, arguments);
+  };
+}
+
+// Note: Make sure to call this ahead of APIs that modify
+// setLocalDescription.length
+function shimParameterlessSetLocalDescription(window, browserDetails) {
+  if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  var nativeSetLocalDescription = window.RTCPeerConnection.prototype.setLocalDescription;
+  if (!nativeSetLocalDescription || nativeSetLocalDescription.length === 0) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.setLocalDescription = function setLocalDescription() {
+    var _this = this;
+    var desc = arguments[0] || {};
+    if (_typeof(desc) !== 'object' || desc.type && desc.sdp) {
+      return nativeSetLocalDescription.apply(this, arguments);
+    }
+    // The remaining steps should technically happen when SLD comes off the
+    // RTCPeerConnection's operations chain (not ahead of going on it), but
+    // this is too difficult to shim. Instead, this shim only covers the
+    // common case where the operations chain is empty. This is imperfect, but
+    // should cover many cases. Rationale: Even if we can't reduce the glare
+    // window to zero on imperfect implementations, there's value in tapping
+    // into the perfect negotiation pattern that several browsers support.
+    desc = {
+      type: desc.type,
+      sdp: desc.sdp
+    };
+    if (!desc.type) {
+      switch (this.signalingState) {
+        case 'stable':
+        case 'have-local-offer':
+        case 'have-remote-pranswer':
+          desc.type = 'offer';
+          break;
+        default:
+          desc.type = 'answer';
+          break;
+      }
+    }
+    if (desc.sdp || desc.type !== 'offer' && desc.type !== 'answer') {
+      return nativeSetLocalDescription.apply(this, [desc]);
+    }
+    var func = desc.type === 'offer' ? this.createOffer : this.createAnswer;
+    return func.apply(this).then(function (d) {
+      return nativeSetLocalDescription.apply(_this, [d]);
+    });
+  };
+}

node_modules/webrtc-adapter/dist/firefox/firefox_shim.js

@@ -0,0 +1,330 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.shimAddTransceiver = shimAddTransceiver;
+exports.shimCreateAnswer = shimCreateAnswer;
+exports.shimCreateOffer = shimCreateOffer;
+Object.defineProperty(exports, "shimGetDisplayMedia", {
+  enumerable: true,
+  get: function get() {
+    return _getdisplaymedia.shimGetDisplayMedia;
+  }
+});
+exports.shimGetParameters = shimGetParameters;
+exports.shimGetStats = shimGetStats;
+Object.defineProperty(exports, "shimGetUserMedia", {
+  enumerable: true,
+  get: function get() {
+    return _getusermedia.shimGetUserMedia;
+  }
+});
+exports.shimOnTrack = shimOnTrack;
+exports.shimPeerConnection = shimPeerConnection;
+exports.shimRTCDataChannel = shimRTCDataChannel;
+exports.shimReceiverGetStats = shimReceiverGetStats;
+exports.shimRemoveStream = shimRemoveStream;
+exports.shimSenderGetStats = shimSenderGetStats;
+var utils = _interopRequireWildcard(require("../utils"));
+var _getusermedia = require("./getusermedia");
+var _getdisplaymedia = require("./getdisplaymedia");
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+function _toConsumableArray(r) { return _arrayWithoutHoles(r) || _iterableToArray(r) || _unsupportedIterableToArray(r) || _nonIterableSpread(); }
+function _nonIterableSpread() { throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }
+function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
+function _iterableToArray(r) { if ("undefined" != typeof Symbol && null != r[Symbol.iterator] || null != r["@@iterator"]) return Array.from(r); }
+function _arrayWithoutHoles(r) { if (Array.isArray(r)) return _arrayLikeToArray(r); }
+function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
+function _defineProperty(e, r, t) { return (r = _toPropertyKey(r)) in e ? Object.defineProperty(e, r, { value: t, enumerable: !0, configurable: !0, writable: !0 }) : e[r] = t, e; }
+function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == _typeof(i) ? i : i + ""; }
+function _toPrimitive(t, r) { if ("object" != _typeof(t) || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != _typeof(i)) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+function shimOnTrack(window) {
+  if (_typeof(window) === 'object' && window.RTCTrackEvent && 'receiver' in window.RTCTrackEvent.prototype && !('transceiver' in window.RTCTrackEvent.prototype)) {
+    Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+      get: function get() {
+        return {
+          receiver: this.receiver
+        };
+      }
+    });
+  }
+}
+function shimPeerConnection(window, browserDetails) {
+  if (_typeof(window) !== 'object' || !(window.RTCPeerConnection || window.mozRTCPeerConnection)) {
+    return; // probably media.peerconnection.enabled=false in about:config
+  }
+  if (!window.RTCPeerConnection && window.mozRTCPeerConnection) {
+    // very basic support for old versions.
+    window.RTCPeerConnection = window.mozRTCPeerConnection;
+  }
+  if (browserDetails.version < 53) {
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate'].forEach(function (method) {
+      var nativeMethod = window.RTCPeerConnection.prototype[method];
+      var methodObj = _defineProperty({}, method, function () {
+        arguments[0] = new (method === 'addIceCandidate' ? window.RTCIceCandidate : window.RTCSessionDescription)(arguments[0]);
+        return nativeMethod.apply(this, arguments);
+      });
+      window.RTCPeerConnection.prototype[method] = methodObj[method];
+    });
+  }
+}
+function shimGetStats(window, browserDetails) {
+  if (_typeof(window) !== 'object' || !(window.RTCPeerConnection || window.mozRTCPeerConnection)) {
+    return; // probably media.peerconnection.enabled=false in about:config
+  }
+  if (browserDetails.version >= 151) {
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1056433
+    return;
+  }
+  var modernStatsTypes = {
+    inboundrtp: 'inbound-rtp',
+    outboundrtp: 'outbound-rtp',
+    candidatepair: 'candidate-pair',
+    localcandidate: 'local-candidate',
+    remotecandidate: 'remote-candidate'
+  };
+  var nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+  window.RTCPeerConnection.prototype.getStats = function getStats() {
+    var _arguments = Array.prototype.slice.call(arguments),
+      selector = _arguments[0],
+      onSucc = _arguments[1],
+      onErr = _arguments[2];
+    if (this.signalingState === 'closed') {
+      // No longer required in FF151+
+      return Promise.resolve(new Map());
+    }
+    return nativeGetStats.apply(this, [selector || null]).then(function (stats) {
+      if (browserDetails.version < 53 && !onSucc) {
+        // Shim only promise getStats with spec-hyphens in type names
+        // Leave callback version alone; misc old uses of forEach before Map
+        try {
+          stats.forEach(function (stat) {
+            stat.type = modernStatsTypes[stat.type] || stat.type;
+          });
+        } catch (e) {
+          if (e.name !== 'TypeError') {
+            throw e;
+          }
+          // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+          stats.forEach(function (stat, i) {
+            stats.set(i, Object.assign({}, stat, {
+              type: modernStatsTypes[stat.type] || stat.type
+            }));
+          });
+        }
+      }
+      return stats;
+    }).then(onSucc, onErr);
+  };
+}
+function shimSenderGetStats(window) {
+  if (!(_typeof(window) === 'object' && window.RTCPeerConnection && window.RTCRtpSender)) {
+    return;
+  }
+  if (window.RTCRtpSender && 'getStats' in window.RTCRtpSender.prototype) {
+    return;
+  }
+  var origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+  if (origGetSenders) {
+    window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+      var _this = this;
+      var senders = origGetSenders.apply(this, []);
+      senders.forEach(function (sender) {
+        return sender._pc = _this;
+      });
+      return senders;
+    };
+  }
+  var origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+  if (origAddTrack) {
+    window.RTCPeerConnection.prototype.addTrack = function addTrack() {
+      var sender = origAddTrack.apply(this, arguments);
+      sender._pc = this;
+      return sender;
+    };
+  }
+  window.RTCRtpSender.prototype.getStats = function getStats() {
+    return this.track ? this._pc.getStats(this.track) : Promise.resolve(new Map());
+  };
+}
+function shimReceiverGetStats(window) {
+  if (!(_typeof(window) === 'object' && window.RTCPeerConnection && window.RTCRtpSender)) {
+    return;
+  }
+  if (window.RTCRtpSender && 'getStats' in window.RTCRtpReceiver.prototype) {
+    return;
+  }
+  var origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
+  if (origGetReceivers) {
+    window.RTCPeerConnection.prototype.getReceivers = function getReceivers() {
+      var _this2 = this;
+      var receivers = origGetReceivers.apply(this, []);
+      receivers.forEach(function (receiver) {
+        return receiver._pc = _this2;
+      });
+      return receivers;
+    };
+  }
+  utils.wrapPeerConnectionEvent(window, 'track', function (e) {
+    e.receiver._pc = e.srcElement;
+    return e;
+  });
+  window.RTCRtpReceiver.prototype.getStats = function getStats() {
+    return this._pc.getStats(this.track);
+  };
+}
+function shimRemoveStream(window) {
+  if (!window.RTCPeerConnection || 'removeStream' in window.RTCPeerConnection.prototype) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
+    var _this3 = this;
+    utils.deprecated('removeStream', 'removeTrack');
+    this.getSenders().forEach(function (sender) {
+      if (sender.track && stream.getTracks().includes(sender.track)) {
+        _this3.removeTrack(sender);
+      }
+    });
+  };
+}
+function shimRTCDataChannel(window) {
+  // rename DataChannel to RTCDataChannel (native fix in FF60):
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1173851
+  if (window.DataChannel && !window.RTCDataChannel) {
+    window.RTCDataChannel = window.DataChannel;
+  }
+}
+function shimAddTransceiver(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!(_typeof(window) === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  var origAddTransceiver = window.RTCPeerConnection.prototype.addTransceiver;
+  if (origAddTransceiver) {
+    window.RTCPeerConnection.prototype.addTransceiver = function addTransceiver() {
+      this.setParametersPromises = [];
+      // WebIDL input coercion and validation
+      var sendEncodings = arguments[1] && arguments[1].sendEncodings;
+      if (sendEncodings === undefined) {
+        sendEncodings = [];
+      }
+      sendEncodings = _toConsumableArray(sendEncodings);
+      var shouldPerformCheck = sendEncodings.length > 0;
+      if (shouldPerformCheck) {
+        // If sendEncodings params are provided, validate grammar
+        sendEncodings.forEach(function (encodingParam) {
+          if ('rid' in encodingParam) {
+            var ridRegex = /^[a-z0-9]{0,16}$/i;
+            if (!ridRegex.test(encodingParam.rid)) {
+              throw new TypeError('Invalid RID value provided.');
+            }
+          }
+          if ('scaleResolutionDownBy' in encodingParam) {
+            if (!(parseFloat(encodingParam.scaleResolutionDownBy) >= 1.0)) {
+              throw new RangeError('scale_resolution_down_by must be >= 1.0');
+            }
+          }
+          if ('maxFramerate' in encodingParam) {
+            if (!(parseFloat(encodingParam.maxFramerate) >= 0)) {
+              throw new RangeError('max_framerate must be >= 0.0');
+            }
+          }
+        });
+      }
+      var transceiver = origAddTransceiver.apply(this, arguments);
+      if (shouldPerformCheck) {
+        // Check if the init options were applied. If not we do this in an
+        // asynchronous way and save the promise reference in a global object.
+        // This is an ugly hack, but at the same time is way more robust than
+        // checking the sender parameters before and after the createOffer
+        // Also note that after the createoffer we are not 100% sure that
+        // the params were asynchronously applied so we might miss the
+        // opportunity to recreate offer.
+        var sender = transceiver.sender;
+        var params = sender.getParameters();
+        if (!('encodings' in params) ||
+        // Avoid being fooled by patched getParameters() below.
+        params.encodings.length === 1 && Object.keys(params.encodings[0]).length === 0) {
+          params.encodings = sendEncodings;
+          sender.sendEncodings = sendEncodings;
+          this.setParametersPromises.push(sender.setParameters(params).then(function () {
+            delete sender.sendEncodings;
+          })["catch"](function () {
+            delete sender.sendEncodings;
+          }));
+        }
+      }
+      return transceiver;
+    };
+  }
+}
+function shimGetParameters(window) {
+  if (!(_typeof(window) === 'object' && window.RTCRtpSender)) {
+    return;
+  }
+  var origGetParameters = window.RTCRtpSender.prototype.getParameters;
+  if (origGetParameters) {
+    window.RTCRtpSender.prototype.getParameters = function getParameters() {
+      var params = origGetParameters.apply(this, arguments);
+      if (!('encodings' in params)) {
+        params.encodings = [].concat(this.sendEncodings || [{}]);
+      }
+      return params;
+    };
+  }
+}
+function shimCreateOffer(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!(_typeof(window) === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+  window.RTCPeerConnection.prototype.createOffer = function createOffer() {
+    var _arguments2 = arguments,
+      _this4 = this;
+    if (this.setParametersPromises && this.setParametersPromises.length) {
+      return Promise.all(this.setParametersPromises).then(function () {
+        return origCreateOffer.apply(_this4, _arguments2);
+      })["finally"](function () {
+        _this4.setParametersPromises = [];
+      });
+    }
+    return origCreateOffer.apply(this, arguments);
+  };
+}
+function shimCreateAnswer(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!(_typeof(window) === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  var origCreateAnswer = window.RTCPeerConnection.prototype.createAnswer;
+  window.RTCPeerConnection.prototype.createAnswer = function createAnswer() {
+    var _arguments3 = arguments,
+      _this5 = this;
+    if (this.setParametersPromises && this.setParametersPromises.length) {
+      return Promise.all(this.setParametersPromises).then(function () {
+        return origCreateAnswer.apply(_this5, _arguments3);
+      })["finally"](function () {
+        _this5.setParametersPromises = [];
+      });
+    }
+    return origCreateAnswer.apply(this, arguments);
+  };
+}

node_modules/webrtc-adapter/dist/firefox/getdisplaymedia.js

@@ -0,0 +1,39 @@
+/*
+ *  Copyright (c) 2018 The adapter.js project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.shimGetDisplayMedia = shimGetDisplayMedia;
+function shimGetDisplayMedia(window, preferredMediaSource) {
+  if (window.navigator.mediaDevices && 'getDisplayMedia' in window.navigator.mediaDevices) {
+    return;
+  }
+  if (!window.navigator.mediaDevices) {
+    return;
+  }
+  window.navigator.mediaDevices.getDisplayMedia = function getDisplayMedia(constraints) {
+    if (!(constraints && constraints.video)) {
+      var err = new DOMException('getDisplayMedia without video ' + 'constraints is undefined');
+      err.name = 'NotFoundError';
+      // from https://heycam.github.io/webidl/#idl-DOMException-error-names
+      err.code = 8;
+      return Promise.reject(err);
+    }
+    if (constraints.video === true) {
+      constraints.video = {
+        mediaSource: preferredMediaSource
+      };
+    } else {
+      constraints.video.mediaSource = preferredMediaSource;
+    }
+    return window.navigator.mediaDevices.getUserMedia(constraints);
+  };
+}

node_modules/webrtc-adapter/dist/firefox/getusermedia.js

@@ -0,0 +1,63 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.shimGetUserMedia = shimGetUserMedia;
+var utils = _interopRequireWildcard(require("../utils"));
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+function shimGetUserMedia(window, browserDetails) {
+  var navigator = window && window.navigator;
+  var MediaStreamTrack = window && window.MediaStreamTrack;
+  navigator.getUserMedia = function (constraints, onSuccess, onError) {
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia', 'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+  if (!(browserDetails.version > 55 && 'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    var remap = function remap(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+    var nativeGetUserMedia = navigator.mediaDevices.getUserMedia.bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function (c) {
+      if (_typeof(c) === 'object' && _typeof(c.audio) === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      var nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function () {
+        var obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      var nativeApplyConstraints = MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function (c) {
+        if (this.kind === 'audio' && _typeof(c) === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+}

node_modules/webrtc-adapter/dist/safari/safari_shim.js

@@ -0,0 +1,345 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.shimAudioContext = shimAudioContext;
+exports.shimCallbacksAPI = shimCallbacksAPI;
+exports.shimConstraints = shimConstraints;
+exports.shimCreateOfferLegacy = shimCreateOfferLegacy;
+exports.shimGetUserMedia = shimGetUserMedia;
+exports.shimLocalStreamsAPI = shimLocalStreamsAPI;
+exports.shimRTCIceServerUrls = shimRTCIceServerUrls;
+exports.shimRemoteStreamsAPI = shimRemoteStreamsAPI;
+exports.shimTrackEventTransceiver = shimTrackEventTransceiver;
+var utils = _interopRequireWildcard(require("../utils"));
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function _interopRequireWildcard(e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, "default": e }; if (null === e || "object" != _typeof(e) && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (var _t in e) "default" !== _t && {}.hasOwnProperty.call(e, _t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, _t)) && (i.get || i.set) ? o(f, _t, i) : f[_t] = e[_t]); return f; })(e, t); }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+function shimLocalStreamsAPI(window) {
+  if (_typeof(window) !== 'object' || !window.RTCPeerConnection) {
+    return;
+  }
+  if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.getLocalStreams = function getLocalStreams() {
+      if (!this._localStreams) {
+        this._localStreams = [];
+      }
+      return this._localStreams;
+    };
+  }
+  if (!('addStream' in window.RTCPeerConnection.prototype)) {
+    var _addTrack = window.RTCPeerConnection.prototype.addTrack;
+    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+      var _this = this;
+      if (!this._localStreams) {
+        this._localStreams = [];
+      }
+      if (!this._localStreams.includes(stream)) {
+        this._localStreams.push(stream);
+      }
+      // Try to emulate Chrome's behaviour of adding in audio-video order.
+      // Safari orders by track id.
+      stream.getAudioTracks().forEach(function (track) {
+        return _addTrack.call(_this, track, stream);
+      });
+      stream.getVideoTracks().forEach(function (track) {
+        return _addTrack.call(_this, track, stream);
+      });
+    };
+    window.RTCPeerConnection.prototype.addTrack = function addTrack(track) {
+      var _this2 = this;
+      for (var _len = arguments.length, streams = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        streams[_key - 1] = arguments[_key];
+      }
+      if (streams) {
+        streams.forEach(function (stream) {
+          if (!_this2._localStreams) {
+            _this2._localStreams = [stream];
+          } else if (!_this2._localStreams.includes(stream)) {
+            _this2._localStreams.push(stream);
+          }
+        });
+      }
+      return _addTrack.apply(this, arguments);
+    };
+  }
+  if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.removeStream = function removeStream(stream) {
+      var _this3 = this;
+      if (!this._localStreams) {
+        this._localStreams = [];
+      }
+      var index = this._localStreams.indexOf(stream);
+      if (index === -1) {
+        return;
+      }
+      this._localStreams.splice(index, 1);
+      var tracks = stream.getTracks();
+      this.getSenders().forEach(function (sender) {
+        if (tracks.includes(sender.track)) {
+          _this3.removeTrack(sender);
+        }
+      });
+    };
+  }
+}
+function shimRemoteStreamsAPI(window) {
+  if (_typeof(window) !== 'object' || !window.RTCPeerConnection) {
+    return;
+  }
+  if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.getRemoteStreams = function getRemoteStreams() {
+      return this._remoteStreams ? this._remoteStreams : [];
+    };
+  }
+  if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+    Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+      get: function get() {
+        return this._onaddstream;
+      },
+      set: function set(f) {
+        var _this4 = this;
+        if (this._onaddstream) {
+          this.removeEventListener('addstream', this._onaddstream);
+          this.removeEventListener('track', this._onaddstreampoly);
+        }
+        this.addEventListener('addstream', this._onaddstream = f);
+        this.addEventListener('track', this._onaddstreampoly = function (e) {
+          e.streams.forEach(function (stream) {
+            if (!_this4._remoteStreams) {
+              _this4._remoteStreams = [];
+            }
+            if (_this4._remoteStreams.includes(stream)) {
+              return;
+            }
+            _this4._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = stream;
+            _this4.dispatchEvent(event);
+          });
+        });
+      }
+    });
+    var origSetRemoteDescription = window.RTCPeerConnection.prototype.setRemoteDescription;
+    window.RTCPeerConnection.prototype.setRemoteDescription = function setRemoteDescription() {
+      var pc = this;
+      if (!this._onaddstreampoly) {
+        this.addEventListener('track', this._onaddstreampoly = function (e) {
+          e.streams.forEach(function (stream) {
+            if (!pc._remoteStreams) {
+              pc._remoteStreams = [];
+            }
+            if (pc._remoteStreams.indexOf(stream) >= 0) {
+              return;
+            }
+            pc._remoteStreams.push(stream);
+            var event = new Event('addstream');
+            event.stream = stream;
+            pc.dispatchEvent(event);
+          });
+        });
+      }
+      return origSetRemoteDescription.apply(pc, arguments);
+    };
+  }
+}
+function shimCallbacksAPI(window) {
+  if (_typeof(window) !== 'object' || !window.RTCPeerConnection) {
+    return;
+  }
+  var prototype = window.RTCPeerConnection.prototype;
+  var origCreateOffer = prototype.createOffer;
+  var origCreateAnswer = prototype.createAnswer;
+  var setLocalDescription = prototype.setLocalDescription;
+  var setRemoteDescription = prototype.setRemoteDescription;
+  var addIceCandidate = prototype.addIceCandidate;
+  prototype.createOffer = function createOffer(successCallback, failureCallback) {
+    var options = arguments.length >= 2 ? arguments[2] : arguments[0];
+    var promise = origCreateOffer.apply(this, [options]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.createAnswer = function createAnswer(successCallback, failureCallback) {
+    var options = arguments.length >= 2 ? arguments[2] : arguments[0];
+    var promise = origCreateAnswer.apply(this, [options]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  var withCallback = function withCallback(description, successCallback, failureCallback) {
+    var promise = setLocalDescription.apply(this, [description]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.setLocalDescription = withCallback;
+  withCallback = function withCallback(description, successCallback, failureCallback) {
+    var promise = setRemoteDescription.apply(this, [description]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.setRemoteDescription = withCallback;
+  withCallback = function withCallback(candidate, successCallback, failureCallback) {
+    var promise = addIceCandidate.apply(this, [candidate]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.addIceCandidate = withCallback;
+}
+function shimGetUserMedia(window) {
+  var navigator = window && window.navigator;
+  if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
+    // shim not needed in Safari 12.1
+    var mediaDevices = navigator.mediaDevices;
+    var _getUserMedia = mediaDevices.getUserMedia.bind(mediaDevices);
+    navigator.mediaDevices.getUserMedia = function (constraints) {
+      return _getUserMedia(shimConstraints(constraints));
+    };
+  }
+  if (!navigator.getUserMedia && navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
+    navigator.getUserMedia = function getUserMedia(constraints, cb, errcb) {
+      navigator.mediaDevices.getUserMedia(constraints).then(cb, errcb);
+    }.bind(navigator);
+  }
+}
+function shimConstraints(constraints) {
+  if (constraints && constraints.video !== undefined) {
+    return Object.assign({}, constraints, {
+      video: utils.compactObject(constraints.video)
+    });
+  }
+  return constraints;
+}
+function shimRTCIceServerUrls(window) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+  var OrigPeerConnection = window.RTCPeerConnection;
+  window.RTCPeerConnection = function RTCPeerConnection(pcConfig, pcConstraints) {
+    if (pcConfig && pcConfig.iceServers) {
+      var newIceServers = [];
+      for (var i = 0; i < pcConfig.iceServers.length; i++) {
+        var server = pcConfig.iceServers[i];
+        if (server.urls === undefined && server.url) {
+          utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+          server = JSON.parse(JSON.stringify(server));
+          server.urls = server.url;
+          delete server.url;
+          newIceServers.push(server);
+        } else {
+          newIceServers.push(pcConfig.iceServers[i]);
+        }
+      }
+      pcConfig.iceServers = newIceServers;
+    }
+    return new OrigPeerConnection(pcConfig, pcConstraints);
+  };
+  window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+  // wrap static methods. Currently just generateCertificate.
+  if ('generateCertificate' in OrigPeerConnection) {
+    Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+      get: function get() {
+        return OrigPeerConnection.generateCertificate;
+      }
+    });
+  }
+}
+function shimTrackEventTransceiver(window) {
+  // Add event.transceiver member over deprecated event.receiver
+  if (_typeof(window) === 'object' && window.RTCTrackEvent && 'receiver' in window.RTCTrackEvent.prototype && !('transceiver' in window.RTCTrackEvent.prototype)) {
+    Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+      get: function get() {
+        return {
+          receiver: this.receiver
+        };
+      }
+    });
+  }
+}
+function shimCreateOfferLegacy(window) {
+  var origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+  window.RTCPeerConnection.prototype.createOffer = function createOffer(offerOptions) {
+    if (offerOptions) {
+      if (typeof offerOptions.offerToReceiveAudio !== 'undefined') {
+        // support bit values
+        offerOptions.offerToReceiveAudio = !!offerOptions.offerToReceiveAudio;
+      }
+      var audioTransceiver = this.getTransceivers().find(function (transceiver) {
+        return transceiver.receiver.track.kind === 'audio';
+      });
+      if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+        if (audioTransceiver.direction === 'sendrecv') {
+          if (audioTransceiver.setDirection) {
+            audioTransceiver.setDirection('sendonly');
+          } else {
+            audioTransceiver.direction = 'sendonly';
+          }
+        } else if (audioTransceiver.direction === 'recvonly') {
+          if (audioTransceiver.setDirection) {
+            audioTransceiver.setDirection('inactive');
+          } else {
+            audioTransceiver.direction = 'inactive';
+          }
+        }
+      } else if (offerOptions.offerToReceiveAudio === true && !audioTransceiver) {
+        this.addTransceiver('audio', {
+          direction: 'recvonly'
+        });
+      }
+      if (typeof offerOptions.offerToReceiveVideo !== 'undefined') {
+        // support bit values
+        offerOptions.offerToReceiveVideo = !!offerOptions.offerToReceiveVideo;
+      }
+      var videoTransceiver = this.getTransceivers().find(function (transceiver) {
+        return transceiver.receiver.track.kind === 'video';
+      });
+      if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+        if (videoTransceiver.direction === 'sendrecv') {
+          if (videoTransceiver.setDirection) {
+            videoTransceiver.setDirection('sendonly');
+          } else {
+            videoTransceiver.direction = 'sendonly';
+          }
+        } else if (videoTransceiver.direction === 'recvonly') {
+          if (videoTransceiver.setDirection) {
+            videoTransceiver.setDirection('inactive');
+          } else {
+            videoTransceiver.direction = 'inactive';
+          }
+        }
+      } else if (offerOptions.offerToReceiveVideo === true && !videoTransceiver) {
+        this.addTransceiver('video', {
+          direction: 'recvonly'
+        });
+      }
+    }
+    return origCreateOffer.apply(this, arguments);
+  };
+}
+function shimAudioContext(window) {
+  if (_typeof(window) !== 'object' || window.AudioContext) {
+    return;
+  }
+  window.AudioContext = window.webkitAudioContext;
+}

node_modules/webrtc-adapter/dist/utils.js

@@ -0,0 +1,280 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.compactObject = compactObject;
+exports.deprecated = deprecated;
+exports.detectBrowser = detectBrowser;
+exports.disableLog = disableLog;
+exports.disableWarnings = disableWarnings;
+exports.extractVersion = extractVersion;
+exports.filterStats = filterStats;
+exports.log = log;
+exports.walkStats = walkStats;
+exports.wrapPeerConnectionEvent = wrapPeerConnectionEvent;
+function _defineProperty(e, r, t) { return (r = _toPropertyKey(r)) in e ? Object.defineProperty(e, r, { value: t, enumerable: !0, configurable: !0, writable: !0 }) : e[r] = t, e; }
+function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == _typeof(i) ? i : i + ""; }
+function _toPrimitive(t, r) { if ("object" != _typeof(t) || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != _typeof(i)) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
+function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
+var logDisabled_ = true;
+var deprecationWarnings_ = true;
+
+/**
+ * Extract browser version out of the provided user agent string.
+ *
+ * @param {!string} uastring userAgent string.
+ * @param {!string} expr Regular expression used as match criteria.
+ * @param {!number} pos position in the version string to be returned.
+ * @return {!number} browser version.
+ */
+function extractVersion(uastring, expr, pos) {
+  var match = uastring.match(expr);
+  return match && match.length >= pos && parseFloat(match[pos], 10);
+}
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object (or false to prevent
+// the event).
+function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  var addEventListener = Object.getOwnPropertyDescriptor(EventTarget.prototype, 'addEventListener');
+  if (!addEventListener.writable) {
+    log('Unable to polyfill events');
+    return;
+  }
+  var proto = window.RTCPeerConnection.prototype;
+  var nativeAddEventListener = proto.addEventListener;
+  proto.addEventListener = function (nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    var wrappedCallback = function wrappedCallback(e) {
+      var modifiedEvent = wrapper(e);
+      if (modifiedEvent) {
+        if (cb.handleEvent) {
+          cb.handleEvent(modifiedEvent);
+        } else {
+          cb(modifiedEvent);
+        }
+      }
+    };
+    this._eventMap = this._eventMap || {};
+    if (!this._eventMap[eventNameToWrap]) {
+      this._eventMap[eventNameToWrap] = new Map();
+    }
+    this._eventMap[eventNameToWrap].set(cb, wrappedCallback);
+    return nativeAddEventListener.apply(this, [nativeEventName, wrappedCallback]);
+  };
+  var nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function (nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap || !this._eventMap[eventNameToWrap]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    if (!this._eventMap[eventNameToWrap].has(cb)) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    var unwrappedCb = this._eventMap[eventNameToWrap].get(cb);
+    this._eventMap[eventNameToWrap]["delete"](cb);
+    if (this._eventMap[eventNameToWrap].size === 0) {
+      delete this._eventMap[eventNameToWrap];
+    }
+    if (Object.keys(this._eventMap).length === 0) {
+      delete this._eventMap;
+    }
+    return nativeRemoveEventListener.apply(this, [nativeEventName, unwrappedCb]);
+  };
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get: function get() {
+      return this['_on' + eventNameToWrap];
+    },
+    set: function set(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap, this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap, this['_on' + eventNameToWrap] = cb);
+      }
+    },
+    enumerable: true,
+    configurable: true
+  });
+}
+function disableLog(bool) {
+  if (typeof bool !== 'boolean') {
+    return new Error('Argument type: ' + _typeof(bool) + '. Please use a boolean.');
+  }
+  logDisabled_ = bool;
+  return bool ? 'adapter.js logging disabled' : 'adapter.js logging enabled';
+}
+
+/**
+ * Disable or enable deprecation warnings
+ * @param {!boolean} bool set to true to disable warnings.
+ */
+function disableWarnings(bool) {
+  if (typeof bool !== 'boolean') {
+    return new Error('Argument type: ' + _typeof(bool) + '. Please use a boolean.');
+  }
+  deprecationWarnings_ = !bool;
+  return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+}
+function log() {
+  if ((typeof window === "undefined" ? "undefined" : _typeof(window)) === 'object') {
+    if (logDisabled_) {
+      return;
+    }
+    if (typeof console !== 'undefined' && typeof console.log === 'function') {
+      console.log.apply(console, arguments);
+    }
+  }
+}
+
+/**
+ * Shows a deprecation warning suggesting the modern and spec-compatible API.
+ */
+function deprecated(oldMethod, newMethod) {
+  if (!deprecationWarnings_) {
+    return;
+  }
+  console.warn(oldMethod + ' is deprecated, please use ' + newMethod + ' instead.');
+}
+
+/**
+ * Browser detector.
+ *
+ * @return {object} result containing browser and version
+ *     properties.
+ */
+function detectBrowser(window) {
+  // Returned result object.
+  var result = {
+    browser: null,
+    version: null
+  };
+
+  // Fail early if it's not a browser
+  if (typeof window === 'undefined' || !window.navigator || !window.navigator.userAgent) {
+    result.browser = 'Not a browser.';
+    return result;
+  }
+  var navigator = window.navigator;
+
+  // Prefer navigator.userAgentData.
+  if (navigator.userAgentData && navigator.userAgentData.brands) {
+    var chromium = navigator.userAgentData.brands.find(function (brand) {
+      return brand.brand === 'Chromium';
+    });
+    if (chromium) {
+      return {
+        browser: 'chrome',
+        version: parseInt(chromium.version, 10)
+      };
+    }
+  }
+  if (navigator.mozGetUserMedia) {
+    // Firefox.
+    result.browser = 'firefox';
+    result.version = parseInt(extractVersion(navigator.userAgent, /Firefox\/(\d+)\./, 1));
+  } else if (navigator.webkitGetUserMedia || window.isSecureContext === false && window.webkitRTCPeerConnection) {
+    // Chrome, Chromium, Webview, Opera.
+    // Version matches Chrome/WebRTC version.
+    // Chrome 74 removed webkitGetUserMedia on http as well so we need the
+    // more complicated fallback to webkitRTCPeerConnection.
+    result.browser = 'chrome';
+    result.version = parseInt(extractVersion(navigator.userAgent, /Chrom(e|ium)\/(\d+)\./, 2)) || null;
+  } else if (window.RTCPeerConnection && navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) {
+    // Safari.
+    result.browser = 'safari';
+    result.version = parseInt(extractVersion(navigator.userAgent, /AppleWebKit\/(\d+)\./, 1));
+    result.supportsUnifiedPlan = window.RTCRtpTransceiver && 'currentDirection' in window.RTCRtpTransceiver.prototype;
+    // Only for internal usage.
+    result._safariVersion = extractVersion(navigator.userAgent, /Version\/(\d+(\.?\d+))/, 1);
+  } else {
+    // Default fallthrough: not supported.
+    result.browser = 'Not a supported browser.';
+    return result;
+  }
+  return result;
+}
+
+/**
+ * Checks if something is an object.
+ *
+ * @param {*} val The something you want to check.
+ * @return true if val is an object, false otherwise.
+ */
+function isObject(val) {
+  return Object.prototype.toString.call(val) === '[object Object]';
+}
+
+/**
+ * Remove all empty objects and undefined values
+ * from a nested object -- an enhanced and vanilla version
+ * of Lodash's `compact`.
+ */
+function compactObject(data) {
+  if (!isObject(data)) {
+    return data;
+  }
+  return Object.keys(data).reduce(function (accumulator, key) {
+    var isObj = isObject(data[key]);
+    var value = isObj ? compactObject(data[key]) : data[key];
+    var isEmptyObject = isObj && !Object.keys(value).length;
+    if (value === undefined || isEmptyObject) {
+      return accumulator;
+    }
+    return Object.assign(accumulator, _defineProperty({}, key, value));
+  }, {});
+}
+
+/* iterates the stats graph recursively. */
+function walkStats(stats, base, resultSet) {
+  if (!base || resultSet.has(base.id)) {
+    return;
+  }
+  resultSet.set(base.id, base);
+  Object.keys(base).forEach(function (name) {
+    if (name.endsWith('Id')) {
+      walkStats(stats, stats.get(base[name]), resultSet);
+    } else if (name.endsWith('Ids')) {
+      base[name].forEach(function (id) {
+        walkStats(stats, stats.get(id), resultSet);
+      });
+    }
+  });
+}
+
+/* filter getStats for a sender/receiver track. */
+function filterStats(result, track, outbound) {
+  var streamStatsType = outbound ? 'outbound-rtp' : 'inbound-rtp';
+  var filteredResult = new Map();
+  if (track === null) {
+    return filteredResult;
+  }
+  var trackStats = [];
+  result.forEach(function (value) {
+    if (value.type === 'track' && value.trackIdentifier === track.id) {
+      trackStats.push(value);
+    }
+  });
+  trackStats.forEach(function (trackStat) {
+    result.forEach(function (stats) {
+      if (stats.type === streamStatsType && stats.trackId === trackStat.id) {
+        walkStats(result, stats, filteredResult);
+      }
+    });
+  });
+  return filteredResult;
+}

node_modules/webrtc-adapter/index.d.ts

@@ -0,0 +1,58 @@
+declare module "webrtc-adapter" {
+    interface IBrowserDetails {
+        browser: string;
+        version?: number;
+        supportsUnifiedPlan?: boolean;
+    }
+
+    interface ICommonShim {
+        shimRTCIceCandidate(window: Window): void;
+        shimMaxMessageSize(window: Window): void;
+        shimSendThrowTypeError(window: Window): void;
+        shimConnectionState(window: Window): void;
+        removeAllowExtmapMixed(window: Window): void;
+    }
+
+    interface IChromeShim {
+        shimMediaStream(window: Window): void;
+        shimOnTrack(window: Window): void;
+        shimGetSendersWithDtmf(window: Window): void;
+        shimSenderReceiverGetStats(window: Window): void;
+        shimAddTrackRemoveTrackWithNative(window: Window): void;
+        shimAddTrackRemoveTrack(window: Window): void;
+        shimPeerConnection(window: Window): void;
+        fixNegotiationNeeded(window: Window): void;
+    }
+
+    interface IFirefoxShim {
+        shimOnTrack(window: Window): void;
+        shimPeerConnection(window: Window): void;
+        shimSenderGetStats(window: Window): void;
+        shimReceiverGetStats(window: Window): void;
+        shimRemoveStream(window: Window): void;
+        shimRTCDataChannel(window: Window): void;
+    }
+
+    interface ISafariShim {
+        shimLocalStreamsAPI(window: Window): void;
+        shimRemoteStreamsAPI(window: Window): void;
+        shimCallbacksAPI(window: Window): void;
+        shimGetUserMedia(window: Window): void;
+        shimConstraints(constraints: MediaStreamConstraints): void;
+        shimRTCIceServerUrls(window: Window): void;
+        shimTrackEventTransceiver(window: Window): void;
+        shimCreateOfferLegacy(window: Window): void;
+    }
+
+    export interface IAdapter {
+        browserDetails: IBrowserDetails;
+        commonShim: ICommonShim;
+        browserShim: IChromeShim | IFirefoxShim | ISafariShim | undefined;
+        extractVersion(uastring: string, expr: string, pos: number): number;
+        disableLog(disable: boolean): void;
+        disableWarnings(disable: boolean): void;
+    }
+
+    const adapter: IAdapter;
+    export default adapter;
+}

node_modules/webrtc-adapter/package.json

@@ -0,0 +1,60 @@
+{
+  "name": "webrtc-adapter",
+  "version": "9.0.5",
+  "description": "A shim to insulate apps from WebRTC spec changes and browser prefix differences",
+  "license": "BSD-3-Clause",
+  "main": "./dist/adapter_core.js",
+  "types": "./index.d.ts",
+  "module": "./src/js/adapter_core.js",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/webrtchacks/adapter.git"
+  },
+  "authors": [
+    "The WebRTC project authors (https://www.webrtc.org/)",
+    "The adapter.js project authors (https://github.com/webrtchacks/adapter/)"
+  ],
+  "scripts": {
+    "preversion": "git stash && npm install && npm update && BROWSER=chrome BVER=stable CI=true npm test && git checkout -B bumpVersion && grunt build && grunt copyForPublish && git add package.json release/* && git commit -m 'Add adapter artifacts' --allow-empty",
+    "version": "",
+    "postversion": "export GITTAG=\"echo $(git describe --abbrev=0 --tags | sed 's/^v//')\" && git push --force --set-upstream origin bumpVersion --follow-tags && git checkout gh-pages && git pull && cp out/adapter.js adapter.js && cp adapter.js adapter-`$GITTAG`.js && rm adapter-latest.js && ln -s adapter-`$GITTAG`.js adapter-latest.js && mkdir -p adapter-`$GITTAG`-variants && cp out/adapter.js adapter-`$GITTAG`-variants/ && cp out/adapter_*.js adapter-`$GITTAG`-variants/ && git add adapter.js adapter-latest.js adapter-`$GITTAG`.js adapter-`$GITTAG`-variants && git commit -m `$GITTAG` && git push --set-upstream origin gh-pages && git checkout main",
+    "prepare": "grunt build",
+    "prepublishonly": "npm test",
+    "test": "grunt && jest test/unit && karma start test/karma.conf.js",
+    "lint-and-unit-tests": "grunt && jest test/unit",
+    "e2e-tests": "grunt && karma start test/karma.conf.js"
+  },
+  "dependencies": {
+    "sdp": "^3.2.0"
+  },
+  "engines": {
+    "npm": ">=3.10.0",
+    "node": ">=6.0.0"
+  },
+  "devDependencies": {
+    "@babel/core": "^7.21.0",
+    "@babel/preset-env": "^7.20.2",
+    "@puppeteer/browsers": "^2.2.0",
+    "babel-preset-env": "^0.0.0",
+    "brfs": "^1.5.0",
+    "chai": "^3.5.0",
+    "eslint-plugin-jest": "^27.4.0",
+    "grunt": "^1.1.0",
+    "grunt-babel": "^8.0.0",
+    "grunt-browserify": "^6.0.0",
+    "grunt-cli": "^1.3.1",
+    "grunt-contrib-clean": "^1.1.0",
+    "grunt-contrib-copy": "^1.0.0",
+    "grunt-eslint": "^24.0.0",
+    "jest": "^29.7.0",
+    "karma": "^6.4.1",
+    "karma-browserify": "^8.1.0",
+    "karma-chai": "^0.1.0",
+    "karma-chrome-launcher": "^2.2.0",
+    "karma-firefox-launcher": "^1.3.0",
+    "karma-mocha": "^2.0.1",
+    "karma-mocha-reporter": "^2.2.3",
+    "karma-safari-launcher": "^1.0.0",
+    "mocha": "^10.2.0"
+  }
+}

node_modules/webrtc-adapter/src/js/adapter_core.js

@@ -0,0 +1,16 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+
+'use strict';
+
+import {adapterFactory} from './adapter_factory.js';
+
+const adapter =
+  adapterFactory({window: typeof window === 'undefined' ? undefined : window});
+export default adapter;

node_modules/webrtc-adapter/src/js/adapter_core5.js

@@ -0,0 +1,16 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+
+'use strict';
+
+import {adapterFactory} from './adapter_factory.js';
+
+const adapter =
+  adapterFactory({window: typeof window === 'undefined' ? undefined : window});
+module.exports = adapter; // this is the difference from adapter_core.

node_modules/webrtc-adapter/src/js/adapter_factory.js

@@ -0,0 +1,139 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+import * as utils from './utils';
+
+// Browser shims.
+import * as chromeShim from './chrome/chrome_shim';
+import * as firefoxShim from './firefox/firefox_shim';
+import * as safariShim from './safari/safari_shim';
+import * as commonShim from './common_shim';
+import * as sdp from 'sdp';
+
+// Shimming starts here.
+export function adapterFactory({window} = {}, options = {
+  shimChrome: true,
+  shimFirefox: true,
+  shimSafari: true,
+}) {
+  // Utils.
+  const logging = utils.log;
+  const browserDetails = utils.detectBrowser(window);
+
+  const adapter = {
+    browserDetails,
+    commonShim,
+    extractVersion: utils.extractVersion,
+    disableLog: utils.disableLog,
+    disableWarnings: utils.disableWarnings,
+    // Expose sdp as a convenience. For production apps include directly.
+    sdp,
+  };
+
+  // Shim browser if found.
+  switch (browserDetails.browser) {
+    case 'chrome':
+      if (!chromeShim || !chromeShim.shimPeerConnection ||
+          !options.shimChrome) {
+        logging('Chrome shim is not included in this adapter release.');
+        return adapter;
+      }
+      if (browserDetails.version === null) {
+        logging('Chrome shim can not determine version, not shimming.');
+        return adapter;
+      }
+      logging('adapter.js shimming chrome.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = chromeShim;
+
+      // Must be called before shimPeerConnection.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+
+      chromeShim.shimGetUserMedia(window, browserDetails);
+      chromeShim.shimMediaStream(window, browserDetails);
+      chromeShim.shimPeerConnection(window, browserDetails);
+      chromeShim.shimOnTrack(window, browserDetails);
+      chromeShim.shimAddTrackRemoveTrack(window, browserDetails);
+      chromeShim.shimGetSendersWithDtmf(window, browserDetails);
+      chromeShim.shimSenderReceiverGetStats(window, browserDetails);
+      chromeShim.fixNegotiationNeeded(window, browserDetails);
+
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimRTCIceCandidateRelayProtocol(window, browserDetails);
+      commonShim.shimConnectionState(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      commonShim.removeExtmapAllowMixed(window, browserDetails);
+      break;
+    case 'firefox':
+      if (!firefoxShim || !firefoxShim.shimPeerConnection ||
+          !options.shimFirefox) {
+        logging('Firefox shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming firefox.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = firefoxShim;
+
+      // Must be called before shimPeerConnection.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+
+      firefoxShim.shimGetUserMedia(window, browserDetails);
+      firefoxShim.shimPeerConnection(window, browserDetails);
+      firefoxShim.shimGetStats(window, browserDetails);
+      firefoxShim.shimOnTrack(window, browserDetails);
+      firefoxShim.shimRemoveStream(window, browserDetails);
+      firefoxShim.shimSenderGetStats(window, browserDetails);
+      firefoxShim.shimReceiverGetStats(window, browserDetails);
+      firefoxShim.shimRTCDataChannel(window, browserDetails);
+      firefoxShim.shimAddTransceiver(window, browserDetails);
+      firefoxShim.shimGetParameters(window, browserDetails);
+      firefoxShim.shimCreateOffer(window, browserDetails);
+      firefoxShim.shimCreateAnswer(window, browserDetails);
+
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimConnectionState(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      break;
+    case 'safari':
+      if (!safariShim || !options.shimSafari) {
+        logging('Safari shim is not included in this adapter release.');
+        return adapter;
+      }
+      logging('adapter.js shimming safari.');
+      // Export to the adapter global object visible in the browser.
+      adapter.browserShim = safariShim;
+
+      // Must be called before shimCallbackAPI.
+      commonShim.shimAddIceCandidateNullOrEmpty(window, browserDetails);
+      commonShim.shimParameterlessSetLocalDescription(window, browserDetails);
+
+      safariShim.shimRTCIceServerUrls(window, browserDetails);
+      safariShim.shimCreateOfferLegacy(window, browserDetails);
+      safariShim.shimCallbacksAPI(window, browserDetails);
+      safariShim.shimLocalStreamsAPI(window, browserDetails);
+      safariShim.shimRemoteStreamsAPI(window, browserDetails);
+      safariShim.shimTrackEventTransceiver(window, browserDetails);
+      safariShim.shimGetUserMedia(window, browserDetails);
+      safariShim.shimAudioContext(window, browserDetails);
+
+      commonShim.shimRTCIceCandidate(window, browserDetails);
+      commonShim.shimRTCIceCandidateRelayProtocol(window, browserDetails);
+      commonShim.shimMaxMessageSize(window, browserDetails);
+      commonShim.shimSendThrowTypeError(window, browserDetails);
+      commonShim.removeExtmapAllowMixed(window, browserDetails);
+      break;
+    default:
+      logging('Unsupported browser!');
+      break;
+  }
+
+  return adapter;
+}

node_modules/webrtc-adapter/src/js/chrome/chrome_shim.js

@@ -0,0 +1,645 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+import * as utils from '../utils.js';
+
+export {shimGetUserMedia} from './getusermedia';
+
+export function shimMediaStream(window) {
+  window.MediaStream = window.MediaStream || window.webkitMediaStream;
+}
+
+export function shimOnTrack(window, browserDetails) {
+  if (browserDetails.version > 102) {
+    // Unified plan is supported so no need to do anything.
+    return;
+  }
+  if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
+      window.RTCPeerConnection.prototype)) {
+    Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
+      get() {
+        return this._ontrack;
+      },
+      set(f) {
+        if (this._ontrack) {
+          this.removeEventListener('track', this._ontrack);
+        }
+        this.addEventListener('track', this._ontrack = f);
+      },
+      enumerable: true,
+      configurable: true
+    });
+    const origSetRemoteDescription =
+        window.RTCPeerConnection.prototype.setRemoteDescription;
+    window.RTCPeerConnection.prototype.setRemoteDescription =
+      function setRemoteDescription() {
+        if (!this._ontrackpoly) {
+          this._ontrackpoly = (e) => {
+            // onaddstream does not fire when a track is added to an existing
+            // stream. But stream.onaddtrack is implemented so we use that.
+            e.stream.addEventListener('addtrack', te => {
+              let receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = this.getReceivers()
+                  .find(r => r.track && r.track.id === te.track.id);
+              } else {
+                receiver = {track: te.track};
+              }
+
+              const event = new Event('track');
+              event.track = te.track;
+              event.receiver = receiver;
+              event.transceiver = {receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            });
+            e.stream.getTracks().forEach(track => {
+              let receiver;
+              if (window.RTCPeerConnection.prototype.getReceivers) {
+                receiver = this.getReceivers()
+                  .find(r => r.track && r.track.id === track.id);
+              } else {
+                receiver = {track};
+              }
+              const event = new Event('track');
+              event.track = track;
+              event.receiver = receiver;
+              event.transceiver = {receiver};
+              event.streams = [e.stream];
+              this.dispatchEvent(event);
+            });
+          };
+          this.addEventListener('addstream', this._ontrackpoly);
+        }
+        return origSetRemoteDescription.apply(this, arguments);
+      };
+  } else {
+    // even if RTCRtpTransceiver is in window, it is only used and
+    // emitted in unified-plan. Unfortunately this means we need
+    // to unconditionally wrap the event.
+    utils.wrapPeerConnectionEvent(window, 'track', e => {
+      if (!e.transceiver) {
+        Object.defineProperty(e, 'transceiver',
+          {value: {receiver: e.receiver}});
+      }
+      return e;
+    });
+  }
+}
+
+export function shimGetSendersWithDtmf(window) {
+  // Overrides addTrack/removeTrack, depends on shimAddTrackRemoveTrack.
+  if (typeof window === 'object' && window.RTCPeerConnection &&
+      !('getSenders' in window.RTCPeerConnection.prototype) &&
+      'createDTMFSender' in window.RTCPeerConnection.prototype) {
+    const shimSenderWithDtmf = function(pc, track) {
+      return {
+        track,
+        get dtmf() {
+          if (this._dtmf === undefined) {
+            if (track.kind === 'audio') {
+              this._dtmf = pc.createDTMFSender(track);
+            } else {
+              this._dtmf = null;
+            }
+          }
+          return this._dtmf;
+        },
+        _pc: pc
+      };
+    };
+
+    // augment addTrack when getSenders is not available.
+    if (!window.RTCPeerConnection.prototype.getSenders) {
+      window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+        this._senders = this._senders || [];
+        return this._senders.slice(); // return a copy of the internal state.
+      };
+      const origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+      window.RTCPeerConnection.prototype.addTrack =
+        function addTrack(track, stream) {
+          let sender = origAddTrack.apply(this, arguments);
+          if (!sender) {
+            sender = shimSenderWithDtmf(this, track);
+            this._senders.push(sender);
+          }
+          return sender;
+        };
+
+      const origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+      window.RTCPeerConnection.prototype.removeTrack =
+        function removeTrack(sender) {
+          origRemoveTrack.apply(this, arguments);
+          const idx = this._senders.indexOf(sender);
+          if (idx !== -1) {
+            this._senders.splice(idx, 1);
+          }
+        };
+    }
+    const origAddStream = window.RTCPeerConnection.prototype.addStream;
+    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+      this._senders = this._senders || [];
+      origAddStream.apply(this, [stream]);
+      stream.getTracks().forEach(track => {
+        this._senders.push(shimSenderWithDtmf(this, track));
+      });
+    };
+
+    const origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+    window.RTCPeerConnection.prototype.removeStream =
+      function removeStream(stream) {
+        this._senders = this._senders || [];
+        origRemoveStream.apply(this, [stream]);
+
+        stream.getTracks().forEach(track => {
+          const sender = this._senders.find(s => s.track === track);
+          if (sender) { // remove sender
+            this._senders.splice(this._senders.indexOf(sender), 1);
+          }
+        });
+      };
+  } else if (typeof window === 'object' && window.RTCPeerConnection &&
+             'getSenders' in window.RTCPeerConnection.prototype &&
+             'createDTMFSender' in window.RTCPeerConnection.prototype &&
+             window.RTCRtpSender &&
+             !('dtmf' in window.RTCRtpSender.prototype)) {
+    const origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+    window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+      const senders = origGetSenders.apply(this, []);
+      senders.forEach(sender => sender._pc = this);
+      return senders;
+    };
+
+    Object.defineProperty(window.RTCRtpSender.prototype, 'dtmf', {
+      get() {
+        if (this._dtmf === undefined) {
+          if (this.track.kind === 'audio') {
+            this._dtmf = this._pc.createDTMFSender(this.track);
+          } else {
+            this._dtmf = null;
+          }
+        }
+        return this._dtmf;
+      }
+    });
+  }
+}
+
+export function shimSenderReceiverGetStats(window, browserDetails) {
+  if (browserDetails.version >= 67) {
+    return;
+  }
+  if (!(typeof window === 'object' && window.RTCPeerConnection &&
+      window.RTCRtpSender && window.RTCRtpReceiver)) {
+    return;
+  }
+
+  // shim sender stats.
+  if (!('getStats' in window.RTCRtpSender.prototype)) {
+    const origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+    if (origGetSenders) {
+      window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+        const senders = origGetSenders.apply(this, []);
+        senders.forEach(sender => sender._pc = this);
+        return senders;
+      };
+    }
+
+    const origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+    if (origAddTrack) {
+      window.RTCPeerConnection.prototype.addTrack = function addTrack() {
+        const sender = origAddTrack.apply(this, arguments);
+        sender._pc = this;
+        return sender;
+      };
+    }
+    window.RTCRtpSender.prototype.getStats = function getStats() {
+      const sender = this;
+      return this._pc.getStats().then(result =>
+        /* Note: this will include stats of all senders that
+         *   send a track with the same id as sender.track as
+         *   it is not possible to identify the RTCRtpSender.
+         */
+        utils.filterStats(result, sender.track, true));
+    };
+  }
+
+  // shim receiver stats.
+  if (!('getStats' in window.RTCRtpReceiver.prototype)) {
+    const origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
+    if (origGetReceivers) {
+      window.RTCPeerConnection.prototype.getReceivers =
+        function getReceivers() {
+          const receivers = origGetReceivers.apply(this, []);
+          receivers.forEach(receiver => receiver._pc = this);
+          return receivers;
+        };
+    }
+    utils.wrapPeerConnectionEvent(window, 'track', e => {
+      e.receiver._pc = e.srcElement;
+      return e;
+    });
+    window.RTCRtpReceiver.prototype.getStats = function getStats() {
+      const receiver = this;
+      return this._pc.getStats().then(result =>
+        utils.filterStats(result, receiver.track, false));
+    };
+  }
+
+  if (!('getStats' in window.RTCRtpSender.prototype &&
+      'getStats' in window.RTCRtpReceiver.prototype)) {
+    return;
+  }
+
+  // shim RTCPeerConnection.getStats(track).
+  const origGetStats = window.RTCPeerConnection.prototype.getStats;
+  window.RTCPeerConnection.prototype.getStats = function getStats() {
+    if (arguments.length > 0 &&
+        arguments[0] instanceof window.MediaStreamTrack) {
+      const track = arguments[0];
+      let sender;
+      let receiver;
+      let err;
+      this.getSenders().forEach(s => {
+        if (s.track === track) {
+          if (sender) {
+            err = true;
+          } else {
+            sender = s;
+          }
+        }
+      });
+      this.getReceivers().forEach(r => {
+        if (r.track === track) {
+          if (receiver) {
+            err = true;
+          } else {
+            receiver = r;
+          }
+        }
+        return r.track === track;
+      });
+      if (err || (sender && receiver)) {
+        return Promise.reject(new DOMException(
+          'There are more than one sender or receiver for the track.',
+          'InvalidAccessError'));
+      } else if (sender) {
+        return sender.getStats();
+      } else if (receiver) {
+        return receiver.getStats();
+      }
+      return Promise.reject(new DOMException(
+        'There is no sender or receiver for the track.',
+        'InvalidAccessError'));
+    }
+    return origGetStats.apply(this, arguments);
+  };
+}
+
+export function shimAddTrackRemoveTrackWithNative(window) {
+  // shim addTrack/removeTrack with native variants in order to make
+  // the interactions with legacy getLocalStreams behave as in other browsers.
+  // Keeps a mapping stream.id => [stream, rtpsenders...]
+  window.RTCPeerConnection.prototype.getLocalStreams =
+    function getLocalStreams() {
+      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+      return Object.keys(this._shimmedLocalStreams)
+        .map(streamId => this._shimmedLocalStreams[streamId][0]);
+    };
+
+  const origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+  window.RTCPeerConnection.prototype.addTrack =
+    function addTrack(track, stream) {
+      if (!stream) {
+        return origAddTrack.apply(this, arguments);
+      }
+      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+
+      const sender = origAddTrack.apply(this, arguments);
+      if (!this._shimmedLocalStreams[stream.id]) {
+        this._shimmedLocalStreams[stream.id] = [stream, sender];
+      } else if (this._shimmedLocalStreams[stream.id].indexOf(sender) === -1) {
+        this._shimmedLocalStreams[stream.id].push(sender);
+      }
+      return sender;
+    };
+
+  const origAddStream = window.RTCPeerConnection.prototype.addStream;
+  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+    this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+
+    stream.getTracks().forEach(track => {
+      const alreadyExists = this.getSenders().find(s => s.track === track);
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+          'InvalidAccessError');
+      }
+    });
+    const existingSenders = this.getSenders();
+    origAddStream.apply(this, arguments);
+    const newSenders = this.getSenders()
+      .filter(newSender => existingSenders.indexOf(newSender) === -1);
+    this._shimmedLocalStreams[stream.id] = [stream].concat(newSenders);
+  };
+
+  const origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+  window.RTCPeerConnection.prototype.removeStream =
+    function removeStream(stream) {
+      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+      delete this._shimmedLocalStreams[stream.id];
+      return origRemoveStream.apply(this, arguments);
+    };
+
+  const origRemoveTrack = window.RTCPeerConnection.prototype.removeTrack;
+  window.RTCPeerConnection.prototype.removeTrack =
+    function removeTrack(sender) {
+      this._shimmedLocalStreams = this._shimmedLocalStreams || {};
+      if (sender) {
+        Object.keys(this._shimmedLocalStreams).forEach(streamId => {
+          const idx = this._shimmedLocalStreams[streamId].indexOf(sender);
+          if (idx !== -1) {
+            this._shimmedLocalStreams[streamId].splice(idx, 1);
+          }
+          if (this._shimmedLocalStreams[streamId].length === 1) {
+            delete this._shimmedLocalStreams[streamId];
+          }
+        });
+      }
+      return origRemoveTrack.apply(this, arguments);
+    };
+}
+
+export function shimAddTrackRemoveTrack(window, browserDetails) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  // shim addTrack and removeTrack.
+  if (window.RTCPeerConnection.prototype.addTrack &&
+      browserDetails.version >= 65) {
+    return shimAddTrackRemoveTrackWithNative(window);
+  }
+
+  // also shim pc.getLocalStreams when addTrack is shimmed
+  // to return the original streams.
+  const origGetLocalStreams = window.RTCPeerConnection.prototype
+    .getLocalStreams;
+  window.RTCPeerConnection.prototype.getLocalStreams =
+    function getLocalStreams() {
+      const nativeStreams = origGetLocalStreams.apply(this);
+      this._reverseStreams = this._reverseStreams || {};
+      return nativeStreams.map(stream => this._reverseStreams[stream.id]);
+    };
+
+  const origAddStream = window.RTCPeerConnection.prototype.addStream;
+  window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+    this._streams = this._streams || {};
+    this._reverseStreams = this._reverseStreams || {};
+
+    stream.getTracks().forEach(track => {
+      const alreadyExists = this.getSenders().find(s => s.track === track);
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+          'InvalidAccessError');
+      }
+    });
+    // Add identity mapping for consistency with addTrack.
+    // Unless this is being used with a stream from addTrack.
+    if (!this._reverseStreams[stream.id]) {
+      const newStream = new window.MediaStream(stream.getTracks());
+      this._streams[stream.id] = newStream;
+      this._reverseStreams[newStream.id] = stream;
+      stream = newStream;
+    }
+    origAddStream.apply(this, [stream]);
+  };
+
+  const origRemoveStream = window.RTCPeerConnection.prototype.removeStream;
+  window.RTCPeerConnection.prototype.removeStream =
+    function removeStream(stream) {
+      this._streams = this._streams || {};
+      this._reverseStreams = this._reverseStreams || {};
+
+      origRemoveStream.apply(this, [(this._streams[stream.id] || stream)]);
+      delete this._reverseStreams[(this._streams[stream.id] ?
+        this._streams[stream.id].id : stream.id)];
+      delete this._streams[stream.id];
+    };
+
+  window.RTCPeerConnection.prototype.addTrack =
+    function addTrack(track, stream) {
+      if (this.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      const streams = [].slice.call(arguments, 1);
+      if (streams.length !== 1 ||
+          !streams[0].getTracks().find(t => t === track)) {
+        // this is not fully correct but all we can manage without
+        // [[associated MediaStreams]] internal slot.
+        throw new DOMException(
+          'The adapter.js addTrack polyfill only supports a single ' +
+          ' stream which is associated with the specified track.',
+          'NotSupportedError');
+      }
+
+      const alreadyExists = this.getSenders().find(s => s.track === track);
+      if (alreadyExists) {
+        throw new DOMException('Track already exists.',
+          'InvalidAccessError');
+      }
+
+      this._streams = this._streams || {};
+      this._reverseStreams = this._reverseStreams || {};
+      const oldStream = this._streams[stream.id];
+      if (oldStream) {
+        // this is using odd Chrome behaviour, use with caution:
+        // https://bugs.chromium.org/p/webrtc/issues/detail?id=7815
+        // Note: we rely on the high-level addTrack/dtmf shim to
+        // create the sender with a dtmf sender.
+        oldStream.addTrack(track);
+
+        // Trigger ONN async.
+        Promise.resolve().then(() => {
+          this.dispatchEvent(new Event('negotiationneeded'));
+        });
+      } else {
+        const newStream = new window.MediaStream([track]);
+        this._streams[stream.id] = newStream;
+        this._reverseStreams[newStream.id] = stream;
+        this.addStream(newStream);
+      }
+      return this.getSenders().find(s => s.track === track);
+    };
+
+  // replace the internal stream id with the external one and
+  // vice versa.
+  function replaceInternalStreamId(pc, description) {
+    let sdp = description.sdp;
+    Object.keys(pc._reverseStreams || []).forEach(internalId => {
+      const externalStream = pc._reverseStreams[internalId];
+      const internalStream = pc._streams[externalStream.id];
+      sdp = sdp.replace(new RegExp(internalStream.id, 'g'),
+        externalStream.id);
+    });
+    return new RTCSessionDescription({
+      type: description.type,
+      sdp
+    });
+  }
+  function replaceExternalStreamId(pc, description) {
+    let sdp = description.sdp;
+    Object.keys(pc._reverseStreams || []).forEach(internalId => {
+      const externalStream = pc._reverseStreams[internalId];
+      const internalStream = pc._streams[externalStream.id];
+      sdp = sdp.replace(new RegExp(externalStream.id, 'g'),
+        internalStream.id);
+    });
+    return new RTCSessionDescription({
+      type: description.type,
+      sdp
+    });
+  }
+  ['createOffer', 'createAnswer'].forEach(function(method) {
+    const nativeMethod = window.RTCPeerConnection.prototype[method];
+    const methodObj = {[method]() {
+      const args = arguments;
+      const isLegacyCall = arguments.length &&
+          typeof arguments[0] === 'function';
+      if (isLegacyCall) {
+        return nativeMethod.apply(this, [
+          (description) => {
+            const desc = replaceInternalStreamId(this, description);
+            args[0].apply(null, [desc]);
+          },
+          (err) => {
+            if (args[1]) {
+              args[1].apply(null, err);
+            }
+          }, arguments[2]
+        ]);
+      }
+      return nativeMethod.apply(this, arguments)
+        .then(description => replaceInternalStreamId(this, description));
+    }};
+    window.RTCPeerConnection.prototype[method] = methodObj[method];
+  });
+
+  const origSetLocalDescription =
+      window.RTCPeerConnection.prototype.setLocalDescription;
+  window.RTCPeerConnection.prototype.setLocalDescription =
+    function setLocalDescription() {
+      if (!arguments.length || !arguments[0].type) {
+        return origSetLocalDescription.apply(this, arguments);
+      }
+      arguments[0] = replaceExternalStreamId(this, arguments[0]);
+      return origSetLocalDescription.apply(this, arguments);
+    };
+
+  // TODO: mangle getStats: https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamstats-streamidentifier
+
+  const origLocalDescription = Object.getOwnPropertyDescriptor(
+    window.RTCPeerConnection.prototype, 'localDescription');
+  Object.defineProperty(window.RTCPeerConnection.prototype,
+    'localDescription', {
+      get() {
+        const description = origLocalDescription.get.apply(this);
+        if (description.type === '') {
+          return description;
+        }
+        return replaceInternalStreamId(this, description);
+      }
+    });
+
+  window.RTCPeerConnection.prototype.removeTrack =
+    function removeTrack(sender) {
+      if (this.signalingState === 'closed') {
+        throw new DOMException(
+          'The RTCPeerConnection\'s signalingState is \'closed\'.',
+          'InvalidStateError');
+      }
+      // We can not yet check for sender instanceof RTCRtpSender
+      // since we shim RTPSender. So we check if sender._pc is set.
+      if (!sender._pc) {
+        throw new DOMException('Argument 1 of RTCPeerConnection.removeTrack ' +
+            'does not implement interface RTCRtpSender.', 'TypeError');
+      }
+      const isLocal = sender._pc === this;
+      if (!isLocal) {
+        throw new DOMException('Sender was not created by this connection.',
+          'InvalidAccessError');
+      }
+
+      // Search for the native stream the senders track belongs to.
+      this._streams = this._streams || {};
+      let stream;
+      Object.keys(this._streams).forEach(streamid => {
+        const hasTrack = this._streams[streamid].getTracks()
+          .find(track => sender.track === track);
+        if (hasTrack) {
+          stream = this._streams[streamid];
+        }
+      });
+
+      if (stream) {
+        if (stream.getTracks().length === 1) {
+          // if this is the last track of the stream, remove the stream. This
+          // takes care of any shimmed _senders.
+          this.removeStream(this._reverseStreams[stream.id]);
+        } else {
+          // relying on the same odd chrome behaviour as above.
+          stream.removeTrack(sender.track);
+        }
+        this.dispatchEvent(new Event('negotiationneeded'));
+      }
+    };
+}
+
+export function shimPeerConnection(window, browserDetails) {
+  if (!window.RTCPeerConnection && window.webkitRTCPeerConnection) {
+    // very basic support for old versions.
+    window.RTCPeerConnection = window.webkitRTCPeerConnection;
+  }
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+
+  // shim implicit creation of RTCSessionDescription/RTCIceCandidate
+  if (browserDetails.version < 53) {
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+      .forEach(function(method) {
+        const nativeMethod = window.RTCPeerConnection.prototype[method];
+        const methodObj = {[method]() {
+          arguments[0] = new ((method === 'addIceCandidate') ?
+            window.RTCIceCandidate :
+            window.RTCSessionDescription)(arguments[0]);
+          return nativeMethod.apply(this, arguments);
+        }};
+        window.RTCPeerConnection.prototype[method] = methodObj[method];
+      });
+  }
+}
+
+// Attempt to fix ONN in plan-b mode.
+export function fixNegotiationNeeded(window, browserDetails) {
+  if (browserDetails.version > 102) {
+    // Plan-B is no longer supported.
+    return;
+  }
+  utils.wrapPeerConnectionEvent(window, 'negotiationneeded', e => {
+    const pc = e.target;
+    if (browserDetails.version < 72 || (pc.getConfiguration &&
+        pc.getConfiguration().sdpSemantics === 'plan-b')) {
+      if (pc.signalingState !== 'stable') {
+        return;
+      }
+    }
+    return e;
+  });
+}

node_modules/webrtc-adapter/src/js/chrome/getusermedia.js

@@ -0,0 +1,189 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+import * as utils from '../utils.js';
+const logging = utils.log;
+
+export function shimGetUserMedia(window, browserDetails) {
+  const navigator = window && window.navigator;
+
+  if (!navigator.mediaDevices) {
+    return;
+  }
+
+  const constraintsToChrome_ = function(c) {
+    if (typeof c !== 'object' || c.mandatory || c.optional) {
+      return c;
+    }
+    const cc = {};
+    Object.keys(c).forEach(key => {
+      if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
+        return;
+      }
+      const r = (typeof c[key] === 'object') ? c[key] : {ideal: c[key]};
+      if (r.exact !== undefined && typeof r.exact === 'number') {
+        r.min = r.max = r.exact;
+      }
+      const oldname_ = function(prefix, name) {
+        if (prefix) {
+          return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+        }
+        return (name === 'deviceId') ? 'sourceId' : name;
+      };
+      if (r.ideal !== undefined) {
+        cc.optional = cc.optional || [];
+        let oc = {};
+        if (typeof r.ideal === 'number') {
+          oc[oldname_('min', key)] = r.ideal;
+          cc.optional.push(oc);
+          oc = {};
+          oc[oldname_('max', key)] = r.ideal;
+          cc.optional.push(oc);
+        } else {
+          oc[oldname_('', key)] = r.ideal;
+          cc.optional.push(oc);
+        }
+      }
+      if (r.exact !== undefined && typeof r.exact !== 'number') {
+        cc.mandatory = cc.mandatory || {};
+        cc.mandatory[oldname_('', key)] = r.exact;
+      } else {
+        ['min', 'max'].forEach(mix => {
+          if (r[mix] !== undefined) {
+            cc.mandatory = cc.mandatory || {};
+            cc.mandatory[oldname_(mix, key)] = r[mix];
+          }
+        });
+      }
+    });
+    if (c.advanced) {
+      cc.optional = (cc.optional || []).concat(c.advanced);
+    }
+    return cc;
+  };
+
+  const shimConstraints_ = function(constraints, func) {
+    if (browserDetails.version >= 61) {
+      return func(constraints);
+    }
+    constraints = JSON.parse(JSON.stringify(constraints));
+    if (constraints && typeof constraints.audio === 'object') {
+      const remap = function(obj, a, b) {
+        if (a in obj && !(b in obj)) {
+          obj[b] = obj[a];
+          delete obj[a];
+        }
+      };
+      constraints = JSON.parse(JSON.stringify(constraints));
+      remap(constraints.audio, 'autoGainControl', 'googAutoGainControl');
+      remap(constraints.audio, 'noiseSuppression', 'googNoiseSuppression');
+      constraints.audio = constraintsToChrome_(constraints.audio);
+    }
+    if (constraints && typeof constraints.video === 'object') {
+      // Shim facingMode for mobile & surface pro.
+      let face = constraints.video.facingMode;
+      face = face && ((typeof face === 'object') ? face : {ideal: face});
+      const getSupportedFacingModeLies = browserDetails.version < 66;
+
+      if ((face && (face.exact === 'user' || face.exact === 'environment' ||
+                    face.ideal === 'user' || face.ideal === 'environment')) &&
+          !(navigator.mediaDevices.getSupportedConstraints &&
+            navigator.mediaDevices.getSupportedConstraints().facingMode &&
+            !getSupportedFacingModeLies)) {
+        delete constraints.video.facingMode;
+        let matches;
+        if (face.exact === 'environment' || face.ideal === 'environment') {
+          matches = ['back', 'rear'];
+        } else if (face.exact === 'user' || face.ideal === 'user') {
+          matches = ['front'];
+        }
+        if (matches) {
+          // Look for matches in label, or use last cam for back (typical).
+          return navigator.mediaDevices.enumerateDevices()
+            .then(devices => {
+              devices = devices.filter(d => d.kind === 'videoinput');
+              let dev = devices.find(d => matches.some(match =>
+                d.label.toLowerCase().includes(match)));
+              if (!dev && devices.length && matches.includes('back')) {
+                dev = devices[devices.length - 1]; // more likely the back cam
+              }
+              if (dev) {
+                constraints.video.deviceId = face.exact
+                  ? {exact: dev.deviceId}
+                  : {ideal: dev.deviceId};
+              }
+              constraints.video = constraintsToChrome_(constraints.video);
+              logging('chrome: ' + JSON.stringify(constraints));
+              return func(constraints);
+            });
+        }
+      }
+      constraints.video = constraintsToChrome_(constraints.video);
+    }
+    logging('chrome: ' + JSON.stringify(constraints));
+    return func(constraints);
+  };
+
+  const shimError_ = function(e) {
+    if (browserDetails.version >= 64) {
+      return e;
+    }
+    return {
+      name: {
+        PermissionDeniedError: 'NotAllowedError',
+        PermissionDismissedError: 'NotAllowedError',
+        InvalidStateError: 'NotAllowedError',
+        DevicesNotFoundError: 'NotFoundError',
+        ConstraintNotSatisfiedError: 'OverconstrainedError',
+        TrackStartError: 'NotReadableError',
+        MediaDeviceFailedDueToShutdown: 'NotAllowedError',
+        MediaDeviceKillSwitchOn: 'NotAllowedError',
+        TabCaptureError: 'AbortError',
+        ScreenCaptureError: 'AbortError',
+        DeviceCaptureError: 'AbortError'
+      }[e.name] || e.name,
+      message: e.message,
+      constraint: e.constraint || e.constraintName,
+      toString() {
+        return this.name + (this.message && ': ') + this.message;
+      }
+    };
+  };
+
+  const getUserMedia_ = function(constraints, onSuccess, onError) {
+    shimConstraints_(constraints, c => {
+      navigator.webkitGetUserMedia(c, onSuccess, e => {
+        if (onError) {
+          onError(shimError_(e));
+        }
+      });
+    });
+  };
+  navigator.getUserMedia = getUserMedia_.bind(navigator);
+
+  // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
+  // function which returns a Promise, it does not accept spec-style
+  // constraints.
+  if (navigator.mediaDevices.getUserMedia) {
+    const origGetUserMedia = navigator.mediaDevices.getUserMedia.
+      bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(cs) {
+      return shimConstraints_(cs, c => origGetUserMedia(c).then(stream => {
+        if (c.audio && !stream.getAudioTracks().length ||
+            c.video && !stream.getVideoTracks().length) {
+          stream.getTracks().forEach(track => {
+            track.stop();
+          });
+          throw new DOMException('', 'NotFoundError');
+        }
+        return stream;
+      }, e => Promise.reject(shimError_(e))));
+    };
+  }
+}

node_modules/webrtc-adapter/src/js/common_shim.js

@@ -0,0 +1,470 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+import SDPUtils from 'sdp';
+import * as utils from './utils';
+
+export function shimRTCIceCandidate(window) {
+  // foundation is arbitrarily chosen as an indicator for full support for
+  // https://w3c.github.io/webrtc-pc/#rtcicecandidate-interface
+  if (!window.RTCIceCandidate || (window.RTCIceCandidate && 'foundation' in
+      window.RTCIceCandidate.prototype)) {
+    return;
+  }
+
+  const NativeRTCIceCandidate = window.RTCIceCandidate;
+  window.RTCIceCandidate = function RTCIceCandidate(args) {
+    // Remove the a= which shouldn't be part of the candidate string.
+    if (typeof args === 'object' && args.candidate &&
+        args.candidate.indexOf('a=') === 0) {
+      args = JSON.parse(JSON.stringify(args));
+      args.candidate = args.candidate.substring(2);
+    }
+
+    if (args.candidate && args.candidate.length) {
+      // Augment the native candidate with the parsed fields.
+      const nativeCandidate = new NativeRTCIceCandidate(args);
+      const parsedCandidate = SDPUtils.parseCandidate(args.candidate);
+      for (const key in parsedCandidate) {
+        if (!(key in nativeCandidate)) {
+          Object.defineProperty(nativeCandidate, key,
+            {value: parsedCandidate[key]});
+        }
+      }
+
+      // Override serializer to not serialize the extra attributes.
+      nativeCandidate.toJSON = function toJSON() {
+        return {
+          candidate: nativeCandidate.candidate,
+          sdpMid: nativeCandidate.sdpMid,
+          sdpMLineIndex: nativeCandidate.sdpMLineIndex,
+          usernameFragment: nativeCandidate.usernameFragment,
+        };
+      };
+      return nativeCandidate;
+    }
+    return new NativeRTCIceCandidate(args);
+  };
+  window.RTCIceCandidate.prototype = NativeRTCIceCandidate.prototype;
+
+  // Hook up the augmented candidate in onicecandidate and
+  // addEventListener('icecandidate', ...)
+  utils.wrapPeerConnectionEvent(window, 'icecandidate', e => {
+    if (e.candidate) {
+      Object.defineProperty(e, 'candidate', {
+        value: new window.RTCIceCandidate(e.candidate),
+        writable: 'false'
+      });
+    }
+    return e;
+  });
+}
+
+export function shimRTCIceCandidateRelayProtocol(window) {
+  if (!window.RTCIceCandidate || (window.RTCIceCandidate && 'relayProtocol' in
+      window.RTCIceCandidate.prototype)) {
+    return;
+  }
+
+  // Hook up the augmented candidate in onicecandidate and
+  // addEventListener('icecandidate', ...)
+  utils.wrapPeerConnectionEvent(window, 'icecandidate', e => {
+    if (e.candidate) {
+      const parsedCandidate = SDPUtils.parseCandidate(e.candidate.candidate);
+      if (parsedCandidate.type === 'relay') {
+        // This is a libwebrtc-specific mapping of local type preference
+        // to relayProtocol.
+        e.candidate.relayProtocol = {
+          0: 'tls',
+          1: 'tcp',
+          2: 'udp',
+        }[parsedCandidate.priority >> 24];
+      }
+    }
+    return e;
+  });
+}
+
+export function shimMaxMessageSize(window, browserDetails) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+
+  if (!('sctp' in window.RTCPeerConnection.prototype)) {
+    Object.defineProperty(window.RTCPeerConnection.prototype, 'sctp', {
+      get() {
+        return typeof this._sctp === 'undefined' ? null : this._sctp;
+      }
+    });
+  }
+
+  const sctpInDescription = function(description) {
+    if (!description || !description.sdp) {
+      return false;
+    }
+    const sections = SDPUtils.splitSections(description.sdp);
+    sections.shift();
+    return sections.some(mediaSection => {
+      const mLine = SDPUtils.parseMLine(mediaSection);
+      return mLine && mLine.kind === 'application'
+          && mLine.protocol.indexOf('SCTP') !== -1;
+    });
+  };
+
+  const getRemoteFirefoxVersion = function(description) {
+    // TODO: Is there a better solution for detecting Firefox?
+    const match = description.sdp.match(/mozilla...THIS_IS_SDPARTA-(\d+)/);
+    if (match === null || match.length < 2) {
+      return -1;
+    }
+    const version = parseInt(match[1], 10);
+    // Test for NaN (yes, this is ugly)
+    return version !== version ? -1 : version;
+  };
+
+  const getCanSendMaxMessageSize = function(remoteIsFirefox) {
+    // Every implementation we know can send at least 64 KiB.
+    // Note: Although Chrome is technically able to send up to 256 KiB, the
+    //       data does not reach the other peer reliably.
+    //       See: https://bugs.chromium.org/p/webrtc/issues/detail?id=8419
+    let canSendMaxMessageSize = 65536;
+    if (browserDetails.browser === 'firefox') {
+      if (browserDetails.version < 57) {
+        if (remoteIsFirefox === -1) {
+          // FF < 57 will send in 16 KiB chunks using the deprecated PPID
+          // fragmentation.
+          canSendMaxMessageSize = 16384;
+        } else {
+          // However, other FF (and RAWRTC) can reassemble PPID-fragmented
+          // messages. Thus, supporting ~2 GiB when sending.
+          canSendMaxMessageSize = 2147483637;
+        }
+      } else if (browserDetails.version < 60) {
+        // Currently, all FF >= 57 will reset the remote maximum message size
+        // to the default value when a data channel is created at a later
+        // stage. :(
+        // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
+        canSendMaxMessageSize =
+          browserDetails.version === 57 ? 65535 : 65536;
+      } else {
+        // FF >= 60 supports sending ~2 GiB
+        canSendMaxMessageSize = 2147483637;
+      }
+    }
+    return canSendMaxMessageSize;
+  };
+
+  const getMaxMessageSize = function(description, remoteIsFirefox) {
+    // Note: 65536 bytes is the default value from the SDP spec. Also,
+    //       every implementation we know supports receiving 65536 bytes.
+    let maxMessageSize = 65536;
+
+    // FF 57 has a slightly incorrect default remote max message size, so
+    // we need to adjust it here to avoid a failure when sending.
+    // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1425697
+    if (browserDetails.browser === 'firefox'
+         && browserDetails.version === 57) {
+      maxMessageSize = 65535;
+    }
+
+    const match = SDPUtils.matchPrefix(description.sdp,
+      'a=max-message-size:');
+    if (match.length > 0) {
+      maxMessageSize = parseInt(match[0].substring(19), 10);
+    } else if (browserDetails.browser === 'firefox' &&
+                remoteIsFirefox !== -1) {
+      // If the maximum message size is not present in the remote SDP and
+      // both local and remote are Firefox, the remote peer can receive
+      // ~2 GiB.
+      maxMessageSize = 2147483637;
+    }
+    return maxMessageSize;
+  };
+
+  const origSetRemoteDescription =
+      window.RTCPeerConnection.prototype.setRemoteDescription;
+  window.RTCPeerConnection.prototype.setRemoteDescription =
+    function setRemoteDescription() {
+      this._sctp = null;
+      // Chrome decided to not expose .sctp in plan-b mode.
+      // As usual, adapter.js has to do an 'ugly worakaround'
+      // to cover up the mess.
+      if (browserDetails.browser === 'chrome' && browserDetails.version >= 76) {
+        const {sdpSemantics} = this.getConfiguration();
+        if (sdpSemantics === 'plan-b') {
+          Object.defineProperty(this, 'sctp', {
+            get() {
+              return typeof this._sctp === 'undefined' ? null : this._sctp;
+            },
+            enumerable: true,
+            configurable: true,
+          });
+        }
+      }
+
+      if (sctpInDescription(arguments[0])) {
+        // Check if the remote is FF.
+        const isFirefox = getRemoteFirefoxVersion(arguments[0]);
+
+        // Get the maximum message size the local peer is capable of sending
+        const canSendMMS = getCanSendMaxMessageSize(isFirefox);
+
+        // Get the maximum message size of the remote peer.
+        const remoteMMS = getMaxMessageSize(arguments[0], isFirefox);
+
+        // Determine final maximum message size
+        let maxMessageSize;
+        if (canSendMMS === 0 && remoteMMS === 0) {
+          maxMessageSize = Number.POSITIVE_INFINITY;
+        } else if (canSendMMS === 0 || remoteMMS === 0) {
+          maxMessageSize = Math.max(canSendMMS, remoteMMS);
+        } else {
+          maxMessageSize = Math.min(canSendMMS, remoteMMS);
+        }
+
+        // Create a dummy RTCSctpTransport object and the 'maxMessageSize'
+        // attribute.
+        const sctp = {};
+        Object.defineProperty(sctp, 'maxMessageSize', {
+          get() {
+            return maxMessageSize;
+          }
+        });
+        this._sctp = sctp;
+      }
+
+      return origSetRemoteDescription.apply(this, arguments);
+    };
+}
+
+export function shimSendThrowTypeError(window, browserDetails) {
+  if (!(window.RTCPeerConnection &&
+      'createDataChannel' in window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  if (browserDetails.browser === 'chrome' && browserDetails.version > 149) {
+    // Fixed by https://issues.chromium.org/issues/490588131
+    return;
+  }
+
+  // Note: Although Firefox >= 57 has a native implementation, the maximum
+  //       message size can be reset for all data channels at a later stage.
+  //       See: https://bugzilla.mozilla.org/show_bug.cgi?id=1426831
+  if (browserDetails.browser === 'firefox' && browserDetails.version > 60) {
+    return;
+  }
+
+  function wrapDcSend(dc, pc) {
+    const origDataChannelSend = dc.send;
+    dc.send = function send() {
+      const data = arguments[0];
+      const length = data.length || data.size || data.byteLength;
+      if (dc.readyState === 'open' &&
+          pc.sctp && length > pc.sctp.maxMessageSize) {
+        throw new TypeError('Message too large (can send a maximum of ' +
+          pc.sctp.maxMessageSize + ' bytes)');
+      }
+      return origDataChannelSend.apply(dc, arguments);
+    };
+  }
+  const origCreateDataChannel =
+    window.RTCPeerConnection.prototype.createDataChannel;
+  window.RTCPeerConnection.prototype.createDataChannel =
+    function createDataChannel() {
+      const dataChannel = origCreateDataChannel.apply(this, arguments);
+      wrapDcSend(dataChannel, this);
+      return dataChannel;
+    };
+  utils.wrapPeerConnectionEvent(window, 'datachannel', e => {
+    wrapDcSend(e.channel, e.target);
+    return e;
+  });
+}
+
+
+/* shims RTCConnectionState by pretending it is the same as iceConnectionState.
+ * See https://bugs.chromium.org/p/webrtc/issues/detail?id=6145#c12
+ * for why this is a valid hack in Chrome. In Firefox it is slightly incorrect
+ * since DTLS failures would be hidden. See
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=1265827
+ * for the Firefox tracking bug.
+ */
+export function shimConnectionState(window) {
+  if (!window.RTCPeerConnection ||
+      'connectionState' in window.RTCPeerConnection.prototype) {
+    return;
+  }
+  const proto = window.RTCPeerConnection.prototype;
+  Object.defineProperty(proto, 'connectionState', {
+    get() {
+      return {
+        completed: 'connected',
+        checking: 'connecting'
+      }[this.iceConnectionState] || this.iceConnectionState;
+    },
+    enumerable: true,
+    configurable: true
+  });
+  Object.defineProperty(proto, 'onconnectionstatechange', {
+    get() {
+      return this._onconnectionstatechange || null;
+    },
+    set(cb) {
+      if (this._onconnectionstatechange) {
+        this.removeEventListener('connectionstatechange',
+          this._onconnectionstatechange);
+        delete this._onconnectionstatechange;
+      }
+      if (cb) {
+        this.addEventListener('connectionstatechange',
+          this._onconnectionstatechange = cb);
+      }
+    },
+    enumerable: true,
+    configurable: true
+  });
+
+  ['setLocalDescription', 'setRemoteDescription'].forEach((method) => {
+    const origMethod = proto[method];
+    proto[method] = function() {
+      if (!this._connectionstatechangepoly) {
+        this._connectionstatechangepoly = e => {
+          const pc = e.target;
+          if (pc._lastConnectionState !== pc.connectionState) {
+            pc._lastConnectionState = pc.connectionState;
+            const newEvent = new Event('connectionstatechange', e);
+            pc.dispatchEvent(newEvent);
+          }
+          return e;
+        };
+        this.addEventListener('iceconnectionstatechange',
+          this._connectionstatechangepoly);
+      }
+      return origMethod.apply(this, arguments);
+    };
+  });
+}
+
+export function removeExtmapAllowMixed(window, browserDetails) {
+  /* remove a=extmap-allow-mixed for webrtc.org < M71 */
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  if (browserDetails.browser === 'chrome' && browserDetails.version >= 71) {
+    return;
+  }
+  if (browserDetails.browser === 'safari' &&
+      browserDetails._safariVersion >= 13.1) {
+    return;
+  }
+  const nativeSRD = window.RTCPeerConnection.prototype.setRemoteDescription;
+  window.RTCPeerConnection.prototype.setRemoteDescription =
+  function setRemoteDescription(desc) {
+    if (desc && desc.sdp && desc.sdp.indexOf('\na=extmap-allow-mixed') !== -1) {
+      const sdp = desc.sdp.split('\n').filter((line) => {
+        return line.trim() !== 'a=extmap-allow-mixed';
+      }).join('\n');
+      // Safari enforces read-only-ness of RTCSessionDescription fields.
+      if (window.RTCSessionDescription &&
+          desc instanceof window.RTCSessionDescription) {
+        arguments[0] = new window.RTCSessionDescription({
+          type: desc.type,
+          sdp,
+        });
+      } else {
+        desc.sdp = sdp;
+      }
+    }
+    return nativeSRD.apply(this, arguments);
+  };
+}
+
+export function shimAddIceCandidateNullOrEmpty(window, browserDetails) {
+  // Support for addIceCandidate(null or undefined)
+  // as well as addIceCandidate({candidate: "", ...})
+  // https://bugs.chromium.org/p/chromium/issues/detail?id=978582
+  // Note: must be called before other polyfills which change the signature.
+  if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  const nativeAddIceCandidate =
+      window.RTCPeerConnection.prototype.addIceCandidate;
+  if (!nativeAddIceCandidate || nativeAddIceCandidate.length === 0) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.addIceCandidate =
+    function addIceCandidate() {
+      if (!arguments[0]) {
+        if (arguments[1]) {
+          arguments[1].apply(null);
+        }
+        return Promise.resolve();
+      }
+      // Firefox 68+ emits and processes {candidate: "", ...}, ignore
+      // in older versions.
+      // Native support for ignoring exists for Chrome M77+.
+      // Safari ignores as well, exact version unknown but works in the same
+      // version that also ignores addIceCandidate(null).
+      if (((browserDetails.browser === 'chrome' && browserDetails.version < 78)
+           || (browserDetails.browser === 'firefox'
+               && browserDetails.version < 68)
+           || (browserDetails.browser === 'safari'))
+          && arguments[0] && arguments[0].candidate === '') {
+        return Promise.resolve();
+      }
+      return nativeAddIceCandidate.apply(this, arguments);
+    };
+}
+
+// Note: Make sure to call this ahead of APIs that modify
+// setLocalDescription.length
+export function shimParameterlessSetLocalDescription(window, browserDetails) {
+  if (!(window.RTCPeerConnection && window.RTCPeerConnection.prototype)) {
+    return;
+  }
+  const nativeSetLocalDescription =
+      window.RTCPeerConnection.prototype.setLocalDescription;
+  if (!nativeSetLocalDescription || nativeSetLocalDescription.length === 0) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.setLocalDescription =
+    function setLocalDescription() {
+      let desc = arguments[0] || {};
+      if (typeof desc !== 'object' || (desc.type && desc.sdp)) {
+        return nativeSetLocalDescription.apply(this, arguments);
+      }
+      // The remaining steps should technically happen when SLD comes off the
+      // RTCPeerConnection's operations chain (not ahead of going on it), but
+      // this is too difficult to shim. Instead, this shim only covers the
+      // common case where the operations chain is empty. This is imperfect, but
+      // should cover many cases. Rationale: Even if we can't reduce the glare
+      // window to zero on imperfect implementations, there's value in tapping
+      // into the perfect negotiation pattern that several browsers support.
+      desc = {type: desc.type, sdp: desc.sdp};
+      if (!desc.type) {
+        switch (this.signalingState) {
+          case 'stable':
+          case 'have-local-offer':
+          case 'have-remote-pranswer':
+            desc.type = 'offer';
+            break;
+          default:
+            desc.type = 'answer';
+            break;
+        }
+      }
+      if (desc.sdp || (desc.type !== 'offer' && desc.type !== 'answer')) {
+        return nativeSetLocalDescription.apply(this, [desc]);
+      }
+      const func = desc.type === 'offer' ? this.createOffer : this.createAnswer;
+      return func.apply(this)
+        .then(d => nativeSetLocalDescription.apply(this, [d]));
+    };
+}

node_modules/webrtc-adapter/src/js/firefox/firefox_shim.js

@@ -0,0 +1,315 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+import * as utils from '../utils';
+export {shimGetUserMedia} from './getusermedia';
+export {shimGetDisplayMedia} from './getdisplaymedia';
+
+export function shimOnTrack(window) {
+  if (typeof window === 'object' && window.RTCTrackEvent &&
+      ('receiver' in window.RTCTrackEvent.prototype) &&
+      !('transceiver' in window.RTCTrackEvent.prototype)) {
+    Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+      get() {
+        return {receiver: this.receiver};
+      }
+    });
+  }
+}
+
+export function shimPeerConnection(window, browserDetails) {
+  if (typeof window !== 'object' ||
+      !(window.RTCPeerConnection || window.mozRTCPeerConnection)) {
+    return; // probably media.peerconnection.enabled=false in about:config
+  }
+  if (!window.RTCPeerConnection && window.mozRTCPeerConnection) {
+    // very basic support for old versions.
+    window.RTCPeerConnection = window.mozRTCPeerConnection;
+  }
+
+  if (browserDetails.version < 53) {
+    // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
+    ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
+      .forEach(function(method) {
+        const nativeMethod = window.RTCPeerConnection.prototype[method];
+        const methodObj = {[method]() {
+          arguments[0] = new ((method === 'addIceCandidate') ?
+            window.RTCIceCandidate :
+            window.RTCSessionDescription)(arguments[0]);
+          return nativeMethod.apply(this, arguments);
+        }};
+        window.RTCPeerConnection.prototype[method] = methodObj[method];
+      });
+  }
+}
+
+export function shimGetStats(window, browserDetails) {
+  if (typeof window !== 'object' ||
+      !(window.RTCPeerConnection || window.mozRTCPeerConnection)) {
+    return; // probably media.peerconnection.enabled=false in about:config
+  }
+  if (browserDetails.version >= 151) {
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1056433
+    return;
+  }
+
+  const modernStatsTypes = {
+    inboundrtp: 'inbound-rtp',
+    outboundrtp: 'outbound-rtp',
+    candidatepair: 'candidate-pair',
+    localcandidate: 'local-candidate',
+    remotecandidate: 'remote-candidate'
+  };
+
+  const nativeGetStats = window.RTCPeerConnection.prototype.getStats;
+  window.RTCPeerConnection.prototype.getStats = function getStats() {
+    const [selector, onSucc, onErr] = arguments;
+    if (this.signalingState === 'closed') {
+      // No longer required in FF151+
+      return Promise.resolve(new Map());
+    }
+    return nativeGetStats.apply(this, [selector || null])
+      .then(stats => {
+        if (browserDetails.version < 53 && !onSucc) {
+          // Shim only promise getStats with spec-hyphens in type names
+          // Leave callback version alone; misc old uses of forEach before Map
+          try {
+            stats.forEach(stat => {
+              stat.type = modernStatsTypes[stat.type] || stat.type;
+            });
+          } catch (e) {
+            if (e.name !== 'TypeError') {
+              throw e;
+            }
+            // Avoid TypeError: "type" is read-only, in old versions. 34-43ish
+            stats.forEach((stat, i) => {
+              stats.set(i, Object.assign({}, stat, {
+                type: modernStatsTypes[stat.type] || stat.type
+              }));
+            });
+          }
+        }
+        return stats;
+      })
+      .then(onSucc, onErr);
+  };
+}
+
+export function shimSenderGetStats(window) {
+  if (!(typeof window === 'object' && window.RTCPeerConnection &&
+      window.RTCRtpSender)) {
+    return;
+  }
+  if (window.RTCRtpSender && 'getStats' in window.RTCRtpSender.prototype) {
+    return;
+  }
+  const origGetSenders = window.RTCPeerConnection.prototype.getSenders;
+  if (origGetSenders) {
+    window.RTCPeerConnection.prototype.getSenders = function getSenders() {
+      const senders = origGetSenders.apply(this, []);
+      senders.forEach(sender => sender._pc = this);
+      return senders;
+    };
+  }
+
+  const origAddTrack = window.RTCPeerConnection.prototype.addTrack;
+  if (origAddTrack) {
+    window.RTCPeerConnection.prototype.addTrack = function addTrack() {
+      const sender = origAddTrack.apply(this, arguments);
+      sender._pc = this;
+      return sender;
+    };
+  }
+  window.RTCRtpSender.prototype.getStats = function getStats() {
+    return this.track ? this._pc.getStats(this.track) :
+      Promise.resolve(new Map());
+  };
+}
+
+export function shimReceiverGetStats(window) {
+  if (!(typeof window === 'object' && window.RTCPeerConnection &&
+      window.RTCRtpSender)) {
+    return;
+  }
+  if (window.RTCRtpSender && 'getStats' in window.RTCRtpReceiver.prototype) {
+    return;
+  }
+  const origGetReceivers = window.RTCPeerConnection.prototype.getReceivers;
+  if (origGetReceivers) {
+    window.RTCPeerConnection.prototype.getReceivers = function getReceivers() {
+      const receivers = origGetReceivers.apply(this, []);
+      receivers.forEach(receiver => receiver._pc = this);
+      return receivers;
+    };
+  }
+  utils.wrapPeerConnectionEvent(window, 'track', e => {
+    e.receiver._pc = e.srcElement;
+    return e;
+  });
+  window.RTCRtpReceiver.prototype.getStats = function getStats() {
+    return this._pc.getStats(this.track);
+  };
+}
+
+export function shimRemoveStream(window) {
+  if (!window.RTCPeerConnection ||
+      'removeStream' in window.RTCPeerConnection.prototype) {
+    return;
+  }
+  window.RTCPeerConnection.prototype.removeStream =
+    function removeStream(stream) {
+      utils.deprecated('removeStream', 'removeTrack');
+      this.getSenders().forEach(sender => {
+        if (sender.track && stream.getTracks().includes(sender.track)) {
+          this.removeTrack(sender);
+        }
+      });
+    };
+}
+
+export function shimRTCDataChannel(window) {
+  // rename DataChannel to RTCDataChannel (native fix in FF60):
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1173851
+  if (window.DataChannel && !window.RTCDataChannel) {
+    window.RTCDataChannel = window.DataChannel;
+  }
+}
+
+export function shimAddTransceiver(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!(typeof window === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  const origAddTransceiver = window.RTCPeerConnection.prototype.addTransceiver;
+  if (origAddTransceiver) {
+    window.RTCPeerConnection.prototype.addTransceiver =
+      function addTransceiver() {
+        this.setParametersPromises = [];
+        // WebIDL input coercion and validation
+        let sendEncodings = arguments[1] && arguments[1].sendEncodings;
+        if (sendEncodings === undefined) {
+          sendEncodings = [];
+        }
+        sendEncodings = [...sendEncodings];
+        const shouldPerformCheck = sendEncodings.length > 0;
+        if (shouldPerformCheck) {
+          // If sendEncodings params are provided, validate grammar
+          sendEncodings.forEach((encodingParam) => {
+            if ('rid' in encodingParam) {
+              const ridRegex = /^[a-z0-9]{0,16}$/i;
+              if (!ridRegex.test(encodingParam.rid)) {
+                throw new TypeError('Invalid RID value provided.');
+              }
+            }
+            if ('scaleResolutionDownBy' in encodingParam) {
+              if (!(parseFloat(encodingParam.scaleResolutionDownBy) >= 1.0)) {
+                throw new RangeError('scale_resolution_down_by must be >= 1.0');
+              }
+            }
+            if ('maxFramerate' in encodingParam) {
+              if (!(parseFloat(encodingParam.maxFramerate) >= 0)) {
+                throw new RangeError('max_framerate must be >= 0.0');
+              }
+            }
+          });
+        }
+        const transceiver = origAddTransceiver.apply(this, arguments);
+        if (shouldPerformCheck) {
+          // Check if the init options were applied. If not we do this in an
+          // asynchronous way and save the promise reference in a global object.
+          // This is an ugly hack, but at the same time is way more robust than
+          // checking the sender parameters before and after the createOffer
+          // Also note that after the createoffer we are not 100% sure that
+          // the params were asynchronously applied so we might miss the
+          // opportunity to recreate offer.
+          const {sender} = transceiver;
+          const params = sender.getParameters();
+          if (!('encodings' in params) ||
+              // Avoid being fooled by patched getParameters() below.
+              (params.encodings.length === 1 &&
+               Object.keys(params.encodings[0]).length === 0)) {
+            params.encodings = sendEncodings;
+            sender.sendEncodings = sendEncodings;
+            this.setParametersPromises.push(sender.setParameters(params)
+              .then(() => {
+                delete sender.sendEncodings;
+              }).catch(() => {
+                delete sender.sendEncodings;
+              })
+            );
+          }
+        }
+        return transceiver;
+      };
+  }
+}
+
+export function shimGetParameters(window) {
+  if (!(typeof window === 'object' && window.RTCRtpSender)) {
+    return;
+  }
+  const origGetParameters = window.RTCRtpSender.prototype.getParameters;
+  if (origGetParameters) {
+    window.RTCRtpSender.prototype.getParameters =
+      function getParameters() {
+        const params = origGetParameters.apply(this, arguments);
+        if (!('encodings' in params)) {
+          params.encodings = [].concat(this.sendEncodings || [{}]);
+        }
+        return params;
+      };
+  }
+}
+
+export function shimCreateOffer(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!(typeof window === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  const origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+  window.RTCPeerConnection.prototype.createOffer = function createOffer() {
+    if (this.setParametersPromises && this.setParametersPromises.length) {
+      return Promise.all(this.setParametersPromises)
+        .then(() => {
+          return origCreateOffer.apply(this, arguments);
+        })
+        .finally(() => {
+          this.setParametersPromises = [];
+        });
+    }
+    return origCreateOffer.apply(this, arguments);
+  };
+}
+
+export function shimCreateAnswer(window) {
+  // https://github.com/webrtcHacks/adapter/issues/998#issuecomment-516921647
+  // Firefox ignores the init sendEncodings options passed to addTransceiver
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1396918
+  if (!(typeof window === 'object' && window.RTCPeerConnection)) {
+    return;
+  }
+  const origCreateAnswer = window.RTCPeerConnection.prototype.createAnswer;
+  window.RTCPeerConnection.prototype.createAnswer = function createAnswer() {
+    if (this.setParametersPromises && this.setParametersPromises.length) {
+      return Promise.all(this.setParametersPromises)
+        .then(() => {
+          return origCreateAnswer.apply(this, arguments);
+        })
+        .finally(() => {
+          this.setParametersPromises = [];
+        });
+    }
+    return origCreateAnswer.apply(this, arguments);
+  };
+}

node_modules/webrtc-adapter/src/js/firefox/getdisplaymedia.js

@@ -0,0 +1,36 @@
+/*
+ *  Copyright (c) 2018 The adapter.js project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+export function shimGetDisplayMedia(window, preferredMediaSource) {
+  if (window.navigator.mediaDevices &&
+    'getDisplayMedia' in window.navigator.mediaDevices) {
+    return;
+  }
+  if (!(window.navigator.mediaDevices)) {
+    return;
+  }
+  window.navigator.mediaDevices.getDisplayMedia =
+    function getDisplayMedia(constraints) {
+      if (!(constraints && constraints.video)) {
+        const err = new DOMException('getDisplayMedia without video ' +
+            'constraints is undefined');
+        err.name = 'NotFoundError';
+        // from https://heycam.github.io/webidl/#idl-DOMException-error-names
+        err.code = 8;
+        return Promise.reject(err);
+      }
+      if (constraints.video === true) {
+        constraints.video = {mediaSource: preferredMediaSource};
+      } else {
+        constraints.video.mediaSource = preferredMediaSource;
+      }
+      return window.navigator.mediaDevices.getUserMedia(constraints);
+    };
+}

node_modules/webrtc-adapter/src/js/firefox/getusermedia.js

@@ -0,0 +1,67 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+import * as utils from '../utils';
+
+export function shimGetUserMedia(window, browserDetails) {
+  const navigator = window && window.navigator;
+  const MediaStreamTrack = window && window.MediaStreamTrack;
+
+  navigator.getUserMedia = function(constraints, onSuccess, onError) {
+    // Replace Firefox 44+'s deprecation warning with unprefixed version.
+    utils.deprecated('navigator.getUserMedia',
+      'navigator.mediaDevices.getUserMedia');
+    navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
+  };
+
+  if (!(browserDetails.version > 55 &&
+      'autoGainControl' in navigator.mediaDevices.getSupportedConstraints())) {
+    const remap = function(obj, a, b) {
+      if (a in obj && !(b in obj)) {
+        obj[b] = obj[a];
+        delete obj[a];
+      }
+    };
+
+    const nativeGetUserMedia = navigator.mediaDevices.getUserMedia.
+      bind(navigator.mediaDevices);
+    navigator.mediaDevices.getUserMedia = function(c) {
+      if (typeof c === 'object' && typeof c.audio === 'object') {
+        c = JSON.parse(JSON.stringify(c));
+        remap(c.audio, 'autoGainControl', 'mozAutoGainControl');
+        remap(c.audio, 'noiseSuppression', 'mozNoiseSuppression');
+      }
+      return nativeGetUserMedia(c);
+    };
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.getSettings) {
+      const nativeGetSettings = MediaStreamTrack.prototype.getSettings;
+      MediaStreamTrack.prototype.getSettings = function() {
+        const obj = nativeGetSettings.apply(this, arguments);
+        remap(obj, 'mozAutoGainControl', 'autoGainControl');
+        remap(obj, 'mozNoiseSuppression', 'noiseSuppression');
+        return obj;
+      };
+    }
+
+    if (MediaStreamTrack && MediaStreamTrack.prototype.applyConstraints) {
+      const nativeApplyConstraints =
+        MediaStreamTrack.prototype.applyConstraints;
+      MediaStreamTrack.prototype.applyConstraints = function(c) {
+        if (this.kind === 'audio' && typeof c === 'object') {
+          c = JSON.parse(JSON.stringify(c));
+          remap(c, 'autoGainControl', 'mozAutoGainControl');
+          remap(c, 'noiseSuppression', 'mozNoiseSuppression');
+        }
+        return nativeApplyConstraints.apply(this, [c]);
+      };
+    }
+  }
+}

node_modules/webrtc-adapter/src/js/safari/safari_shim.js

@@ -0,0 +1,352 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+'use strict';
+import * as utils from '../utils';
+
+export function shimLocalStreamsAPI(window) {
+  if (typeof window !== 'object' || !window.RTCPeerConnection) {
+    return;
+  }
+  if (!('getLocalStreams' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.getLocalStreams =
+      function getLocalStreams() {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        return this._localStreams;
+      };
+  }
+  if (!('addStream' in window.RTCPeerConnection.prototype)) {
+    const _addTrack = window.RTCPeerConnection.prototype.addTrack;
+    window.RTCPeerConnection.prototype.addStream = function addStream(stream) {
+      if (!this._localStreams) {
+        this._localStreams = [];
+      }
+      if (!this._localStreams.includes(stream)) {
+        this._localStreams.push(stream);
+      }
+      // Try to emulate Chrome's behaviour of adding in audio-video order.
+      // Safari orders by track id.
+      stream.getAudioTracks().forEach(track => _addTrack.call(this, track,
+        stream));
+      stream.getVideoTracks().forEach(track => _addTrack.call(this, track,
+        stream));
+    };
+
+    window.RTCPeerConnection.prototype.addTrack =
+      function addTrack(track, ...streams) {
+        if (streams) {
+          streams.forEach((stream) => {
+            if (!this._localStreams) {
+              this._localStreams = [stream];
+            } else if (!this._localStreams.includes(stream)) {
+              this._localStreams.push(stream);
+            }
+          });
+        }
+        return _addTrack.apply(this, arguments);
+      };
+  }
+  if (!('removeStream' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.removeStream =
+      function removeStream(stream) {
+        if (!this._localStreams) {
+          this._localStreams = [];
+        }
+        const index = this._localStreams.indexOf(stream);
+        if (index === -1) {
+          return;
+        }
+        this._localStreams.splice(index, 1);
+        const tracks = stream.getTracks();
+        this.getSenders().forEach(sender => {
+          if (tracks.includes(sender.track)) {
+            this.removeTrack(sender);
+          }
+        });
+      };
+  }
+}
+
+export function shimRemoteStreamsAPI(window) {
+  if (typeof window !== 'object' || !window.RTCPeerConnection) {
+    return;
+  }
+  if (!('getRemoteStreams' in window.RTCPeerConnection.prototype)) {
+    window.RTCPeerConnection.prototype.getRemoteStreams =
+      function getRemoteStreams() {
+        return this._remoteStreams ? this._remoteStreams : [];
+      };
+  }
+  if (!('onaddstream' in window.RTCPeerConnection.prototype)) {
+    Object.defineProperty(window.RTCPeerConnection.prototype, 'onaddstream', {
+      get() {
+        return this._onaddstream;
+      },
+      set(f) {
+        if (this._onaddstream) {
+          this.removeEventListener('addstream', this._onaddstream);
+          this.removeEventListener('track', this._onaddstreampoly);
+        }
+        this.addEventListener('addstream', this._onaddstream = f);
+        this.addEventListener('track', this._onaddstreampoly = (e) => {
+          e.streams.forEach(stream => {
+            if (!this._remoteStreams) {
+              this._remoteStreams = [];
+            }
+            if (this._remoteStreams.includes(stream)) {
+              return;
+            }
+            this._remoteStreams.push(stream);
+            const event = new Event('addstream');
+            event.stream = stream;
+            this.dispatchEvent(event);
+          });
+        });
+      }
+    });
+    const origSetRemoteDescription =
+      window.RTCPeerConnection.prototype.setRemoteDescription;
+    window.RTCPeerConnection.prototype.setRemoteDescription =
+      function setRemoteDescription() {
+        const pc = this;
+        if (!this._onaddstreampoly) {
+          this.addEventListener('track', this._onaddstreampoly = function(e) {
+            e.streams.forEach(stream => {
+              if (!pc._remoteStreams) {
+                pc._remoteStreams = [];
+              }
+              if (pc._remoteStreams.indexOf(stream) >= 0) {
+                return;
+              }
+              pc._remoteStreams.push(stream);
+              const event = new Event('addstream');
+              event.stream = stream;
+              pc.dispatchEvent(event);
+            });
+          });
+        }
+        return origSetRemoteDescription.apply(pc, arguments);
+      };
+  }
+}
+
+export function shimCallbacksAPI(window) {
+  if (typeof window !== 'object' || !window.RTCPeerConnection) {
+    return;
+  }
+  const prototype = window.RTCPeerConnection.prototype;
+  const origCreateOffer = prototype.createOffer;
+  const origCreateAnswer = prototype.createAnswer;
+  const setLocalDescription = prototype.setLocalDescription;
+  const setRemoteDescription = prototype.setRemoteDescription;
+  const addIceCandidate = prototype.addIceCandidate;
+
+  prototype.createOffer =
+    function createOffer(successCallback, failureCallback) {
+      const options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      const promise = origCreateOffer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+  prototype.createAnswer =
+    function createAnswer(successCallback, failureCallback) {
+      const options = (arguments.length >= 2) ? arguments[2] : arguments[0];
+      const promise = origCreateAnswer.apply(this, [options]);
+      if (!failureCallback) {
+        return promise;
+      }
+      promise.then(successCallback, failureCallback);
+      return Promise.resolve();
+    };
+
+  let withCallback = function(description, successCallback, failureCallback) {
+    const promise = setLocalDescription.apply(this, [description]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.setLocalDescription = withCallback;
+
+  withCallback = function(description, successCallback, failureCallback) {
+    const promise = setRemoteDescription.apply(this, [description]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.setRemoteDescription = withCallback;
+
+  withCallback = function(candidate, successCallback, failureCallback) {
+    const promise = addIceCandidate.apply(this, [candidate]);
+    if (!failureCallback) {
+      return promise;
+    }
+    promise.then(successCallback, failureCallback);
+    return Promise.resolve();
+  };
+  prototype.addIceCandidate = withCallback;
+}
+
+export function shimGetUserMedia(window) {
+  const navigator = window && window.navigator;
+
+  if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
+    // shim not needed in Safari 12.1
+    const mediaDevices = navigator.mediaDevices;
+    const _getUserMedia = mediaDevices.getUserMedia.bind(mediaDevices);
+    navigator.mediaDevices.getUserMedia = (constraints) => {
+      return _getUserMedia(shimConstraints(constraints));
+    };
+  }
+
+  if (!navigator.getUserMedia && navigator.mediaDevices &&
+    navigator.mediaDevices.getUserMedia) {
+    navigator.getUserMedia = function getUserMedia(constraints, cb, errcb) {
+      navigator.mediaDevices.getUserMedia(constraints)
+        .then(cb, errcb);
+    }.bind(navigator);
+  }
+}
+
+export function shimConstraints(constraints) {
+  if (constraints && constraints.video !== undefined) {
+    return Object.assign({},
+      constraints,
+      {video: utils.compactObject(constraints.video)}
+    );
+  }
+
+  return constraints;
+}
+
+export function shimRTCIceServerUrls(window) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  // migrate from non-spec RTCIceServer.url to RTCIceServer.urls
+  const OrigPeerConnection = window.RTCPeerConnection;
+  window.RTCPeerConnection =
+    function RTCPeerConnection(pcConfig, pcConstraints) {
+      if (pcConfig && pcConfig.iceServers) {
+        const newIceServers = [];
+        for (let i = 0; i < pcConfig.iceServers.length; i++) {
+          let server = pcConfig.iceServers[i];
+          if (server.urls === undefined && server.url) {
+            utils.deprecated('RTCIceServer.url', 'RTCIceServer.urls');
+            server = JSON.parse(JSON.stringify(server));
+            server.urls = server.url;
+            delete server.url;
+            newIceServers.push(server);
+          } else {
+            newIceServers.push(pcConfig.iceServers[i]);
+          }
+        }
+        pcConfig.iceServers = newIceServers;
+      }
+      return new OrigPeerConnection(pcConfig, pcConstraints);
+    };
+  window.RTCPeerConnection.prototype = OrigPeerConnection.prototype;
+  // wrap static methods. Currently just generateCertificate.
+  if ('generateCertificate' in OrigPeerConnection) {
+    Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
+      get() {
+        return OrigPeerConnection.generateCertificate;
+      }
+    });
+  }
+}
+
+export function shimTrackEventTransceiver(window) {
+  // Add event.transceiver member over deprecated event.receiver
+  if (typeof window === 'object' && window.RTCTrackEvent &&
+      'receiver' in window.RTCTrackEvent.prototype &&
+      !('transceiver' in window.RTCTrackEvent.prototype)) {
+    Object.defineProperty(window.RTCTrackEvent.prototype, 'transceiver', {
+      get() {
+        return {receiver: this.receiver};
+      }
+    });
+  }
+}
+
+export function shimCreateOfferLegacy(window) {
+  const origCreateOffer = window.RTCPeerConnection.prototype.createOffer;
+  window.RTCPeerConnection.prototype.createOffer =
+    function createOffer(offerOptions) {
+      if (offerOptions) {
+        if (typeof offerOptions.offerToReceiveAudio !== 'undefined') {
+          // support bit values
+          offerOptions.offerToReceiveAudio =
+            !!offerOptions.offerToReceiveAudio;
+        }
+        const audioTransceiver = this.getTransceivers().find(transceiver =>
+          transceiver.receiver.track.kind === 'audio');
+        if (offerOptions.offerToReceiveAudio === false && audioTransceiver) {
+          if (audioTransceiver.direction === 'sendrecv') {
+            if (audioTransceiver.setDirection) {
+              audioTransceiver.setDirection('sendonly');
+            } else {
+              audioTransceiver.direction = 'sendonly';
+            }
+          } else if (audioTransceiver.direction === 'recvonly') {
+            if (audioTransceiver.setDirection) {
+              audioTransceiver.setDirection('inactive');
+            } else {
+              audioTransceiver.direction = 'inactive';
+            }
+          }
+        } else if (offerOptions.offerToReceiveAudio === true &&
+            !audioTransceiver) {
+          this.addTransceiver('audio', {direction: 'recvonly'});
+        }
+
+        if (typeof offerOptions.offerToReceiveVideo !== 'undefined') {
+          // support bit values
+          offerOptions.offerToReceiveVideo =
+            !!offerOptions.offerToReceiveVideo;
+        }
+        const videoTransceiver = this.getTransceivers().find(transceiver =>
+          transceiver.receiver.track.kind === 'video');
+        if (offerOptions.offerToReceiveVideo === false && videoTransceiver) {
+          if (videoTransceiver.direction === 'sendrecv') {
+            if (videoTransceiver.setDirection) {
+              videoTransceiver.setDirection('sendonly');
+            } else {
+              videoTransceiver.direction = 'sendonly';
+            }
+          } else if (videoTransceiver.direction === 'recvonly') {
+            if (videoTransceiver.setDirection) {
+              videoTransceiver.setDirection('inactive');
+            } else {
+              videoTransceiver.direction = 'inactive';
+            }
+          }
+        } else if (offerOptions.offerToReceiveVideo === true &&
+            !videoTransceiver) {
+          this.addTransceiver('video', {direction: 'recvonly'});
+        }
+      }
+      return origCreateOffer.apply(this, arguments);
+    };
+}
+
+export function shimAudioContext(window) {
+  if (typeof window !== 'object' || window.AudioContext) {
+    return;
+  }
+  window.AudioContext = window.webkitAudioContext;
+}
+

node_modules/webrtc-adapter/src/js/utils.js

@@ -0,0 +1,283 @@
+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree.
+ */
+/* eslint-env node */
+'use strict';
+
+let logDisabled_ = true;
+let deprecationWarnings_ = true;
+
+/**
+ * Extract browser version out of the provided user agent string.
+ *
+ * @param {!string} uastring userAgent string.
+ * @param {!string} expr Regular expression used as match criteria.
+ * @param {!number} pos position in the version string to be returned.
+ * @return {!number} browser version.
+ */
+export function extractVersion(uastring, expr, pos) {
+  const match = uastring.match(expr);
+  return match && match.length >= pos && parseFloat(match[pos], 10);
+}
+
+// Wraps the peerconnection event eventNameToWrap in a function
+// which returns the modified event object (or false to prevent
+// the event).
+export function wrapPeerConnectionEvent(window, eventNameToWrap, wrapper) {
+  if (!window.RTCPeerConnection) {
+    return;
+  }
+  const addEventListener = Object.getOwnPropertyDescriptor(
+    EventTarget.prototype, 'addEventListener');
+  if (!addEventListener.writable) {
+    log('Unable to polyfill events');
+    return;
+  }
+  const proto = window.RTCPeerConnection.prototype;
+  const nativeAddEventListener = proto.addEventListener;
+
+  proto.addEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap) {
+      return nativeAddEventListener.apply(this, arguments);
+    }
+    const wrappedCallback = (e) => {
+      const modifiedEvent = wrapper(e);
+      if (modifiedEvent) {
+        if (cb.handleEvent) {
+          cb.handleEvent(modifiedEvent);
+        } else {
+          cb(modifiedEvent);
+        }
+      }
+    };
+    this._eventMap = this._eventMap || {};
+    if (!this._eventMap[eventNameToWrap]) {
+      this._eventMap[eventNameToWrap] = new Map();
+    }
+    this._eventMap[eventNameToWrap].set(cb, wrappedCallback);
+    return nativeAddEventListener.apply(this, [nativeEventName,
+      wrappedCallback]);
+  };
+
+  const nativeRemoveEventListener = proto.removeEventListener;
+  proto.removeEventListener = function(nativeEventName, cb) {
+    if (nativeEventName !== eventNameToWrap || !this._eventMap
+        || !this._eventMap[eventNameToWrap]) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    if (!this._eventMap[eventNameToWrap].has(cb)) {
+      return nativeRemoveEventListener.apply(this, arguments);
+    }
+    const unwrappedCb = this._eventMap[eventNameToWrap].get(cb);
+    this._eventMap[eventNameToWrap].delete(cb);
+    if (this._eventMap[eventNameToWrap].size === 0) {
+      delete this._eventMap[eventNameToWrap];
+    }
+    if (Object.keys(this._eventMap).length === 0) {
+      delete this._eventMap;
+    }
+    return nativeRemoveEventListener.apply(this, [nativeEventName,
+      unwrappedCb]);
+  };
+
+  Object.defineProperty(proto, 'on' + eventNameToWrap, {
+    get() {
+      return this['_on' + eventNameToWrap];
+    },
+    set(cb) {
+      if (this['_on' + eventNameToWrap]) {
+        this.removeEventListener(eventNameToWrap,
+          this['_on' + eventNameToWrap]);
+        delete this['_on' + eventNameToWrap];
+      }
+      if (cb) {
+        this.addEventListener(eventNameToWrap,
+          this['_on' + eventNameToWrap] = cb);
+      }
+    },
+    enumerable: true,
+    configurable: true
+  });
+}
+
+export function disableLog(bool) {
+  if (typeof bool !== 'boolean') {
+    return new Error('Argument type: ' + typeof bool +
+        '. Please use a boolean.');
+  }
+  logDisabled_ = bool;
+  return (bool) ? 'adapter.js logging disabled' :
+    'adapter.js logging enabled';
+}
+
+/**
+ * Disable or enable deprecation warnings
+ * @param {!boolean} bool set to true to disable warnings.
+ */
+export function disableWarnings(bool) {
+  if (typeof bool !== 'boolean') {
+    return new Error('Argument type: ' + typeof bool +
+        '. Please use a boolean.');
+  }
+  deprecationWarnings_ = !bool;
+  return 'adapter.js deprecation warnings ' + (bool ? 'disabled' : 'enabled');
+}
+
+export function log() {
+  if (typeof window === 'object') {
+    if (logDisabled_) {
+      return;
+    }
+    if (typeof console !== 'undefined' && typeof console.log === 'function') {
+      console.log.apply(console, arguments);
+    }
+  }
+}
+
+/**
+ * Shows a deprecation warning suggesting the modern and spec-compatible API.
+ */
+export function deprecated(oldMethod, newMethod) {
+  if (!deprecationWarnings_) {
+    return;
+  }
+  console.warn(oldMethod + ' is deprecated, please use ' + newMethod +
+      ' instead.');
+}
+
+/**
+ * Browser detector.
+ *
+ * @return {object} result containing browser and version
+ *     properties.
+ */
+export function detectBrowser(window) {
+  // Returned result object.
+  const result = {browser: null, version: null};
+
+  // Fail early if it's not a browser
+  if (typeof window === 'undefined' || !window.navigator ||
+      !window.navigator.userAgent) {
+    result.browser = 'Not a browser.';
+    return result;
+  }
+
+  const {navigator} = window;
+
+  // Prefer navigator.userAgentData.
+  if (navigator.userAgentData && navigator.userAgentData.brands) {
+    const chromium = navigator.userAgentData.brands.find((brand) => {
+      return brand.brand === 'Chromium';
+    });
+    if (chromium) {
+      return {browser: 'chrome', version: parseInt(chromium.version, 10)};
+    }
+  }
+
+  if (navigator.mozGetUserMedia) { // Firefox.
+    result.browser = 'firefox';
+    result.version = parseInt(extractVersion(navigator.userAgent,
+      /Firefox\/(\d+)\./, 1));
+  } else if (navigator.webkitGetUserMedia ||
+      (window.isSecureContext === false && window.webkitRTCPeerConnection)) {
+    // Chrome, Chromium, Webview, Opera.
+    // Version matches Chrome/WebRTC version.
+    // Chrome 74 removed webkitGetUserMedia on http as well so we need the
+    // more complicated fallback to webkitRTCPeerConnection.
+    result.browser = 'chrome';
+    result.version = parseInt(extractVersion(navigator.userAgent,
+      /Chrom(e|ium)\/(\d+)\./, 2)) || null;
+  } else if (window.RTCPeerConnection &&
+      navigator.userAgent.match(/AppleWebKit\/(\d+)\./)) { // Safari.
+    result.browser = 'safari';
+    result.version = parseInt(extractVersion(navigator.userAgent,
+      /AppleWebKit\/(\d+)\./, 1));
+    result.supportsUnifiedPlan = window.RTCRtpTransceiver &&
+        'currentDirection' in window.RTCRtpTransceiver.prototype;
+    // Only for internal usage.
+    result._safariVersion = extractVersion(navigator.userAgent,
+      /Version\/(\d+(\.?\d+))/, 1);
+  } else { // Default fallthrough: not supported.
+    result.browser = 'Not a supported browser.';
+    return result;
+  }
+
+  return result;
+}
+
+/**
+ * Checks if something is an object.
+ *
+ * @param {*} val The something you want to check.
+ * @return true if val is an object, false otherwise.
+ */
+function isObject(val) {
+  return Object.prototype.toString.call(val) === '[object Object]';
+}
+
+/**
+ * Remove all empty objects and undefined values
+ * from a nested object -- an enhanced and vanilla version
+ * of Lodash's `compact`.
+ */
+export function compactObject(data) {
+  if (!isObject(data)) {
+    return data;
+  }
+
+  return Object.keys(data).reduce(function(accumulator, key) {
+    const isObj = isObject(data[key]);
+    const value = isObj ? compactObject(data[key]) : data[key];
+    const isEmptyObject = isObj && !Object.keys(value).length;
+    if (value === undefined || isEmptyObject) {
+      return accumulator;
+    }
+    return Object.assign(accumulator, {[key]: value});
+  }, {});
+}
+
+/* iterates the stats graph recursively. */
+export function walkStats(stats, base, resultSet) {
+  if (!base || resultSet.has(base.id)) {
+    return;
+  }
+  resultSet.set(base.id, base);
+  Object.keys(base).forEach(name => {
+    if (name.endsWith('Id')) {
+      walkStats(stats, stats.get(base[name]), resultSet);
+    } else if (name.endsWith('Ids')) {
+      base[name].forEach(id => {
+        walkStats(stats, stats.get(id), resultSet);
+      });
+    }
+  });
+}
+
+/* filter getStats for a sender/receiver track. */
+export function filterStats(result, track, outbound) {
+  const streamStatsType = outbound ? 'outbound-rtp' : 'inbound-rtp';
+  const filteredResult = new Map();
+  if (track === null) {
+    return filteredResult;
+  }
+  const trackStats = [];
+  result.forEach(value => {
+    if (value.type === 'track' &&
+        value.trackIdentifier === track.id) {
+      trackStats.push(value);
+    }
+  });
+  trackStats.forEach(trackStat => {
+    result.forEach(stats => {
+      if (stats.type === streamStatsType && stats.trackId === trackStat.id) {
+        walkStats(result, stats, filteredResult);
+      }
+    });
+  });
+  return filteredResult;
+}
+