lib-jitsi-meet/modules/RTC/adapter.screenshare.js

/*! adapterjs - v0.14.0 - 2016-10-03 */
var console = require("jitsi-meet-logger").getLogger(__filename);
// Adapter's interface.
var AdapterJS = AdapterJS || {};

// Browserify compatibility
if(typeof exports !== 'undefined') {
  module.exports = AdapterJS;
}

AdapterJS.options = AdapterJS.options || {};

// uncomment to get virtual webcams
// AdapterJS.options.getAllCams = true;

// uncomment to prevent the install prompt when the plugin in not yet installed
// AdapterJS.options.hidePluginInstallPrompt = true;

// AdapterJS version
AdapterJS.VERSION = '0.14.0';

// This function will be called when the WebRTC API is ready to be used
// Whether it is the native implementation (Chrome, Firefox, Opera) or
// the plugin
// You may Override this function to synchronise the start of your application
// with the WebRTC API being ready.
// If you decide not to override use this synchronisation, it may result in
// an extensive CPU usage on the plugin start (once per tab loaded)
// Params:
//    - isUsingPlugin: true is the WebRTC plugin is being used, false otherwise
//
AdapterJS.onwebrtcready = AdapterJS.onwebrtcready || function(isUsingPlugin) {
  // The WebRTC API is ready.
  // Override me and do whatever you want here
};

// New interface to store multiple callbacks, private
AdapterJS._onwebrtcreadies = [];

// Sets a callback function to be called when the WebRTC interface is ready.
// The first argument is the function to callback.\
// Throws an error if the first argument is not a function
AdapterJS.webRTCReady = function (callback) {
  if (typeof callback !== 'function') {
    throw new Error('Callback provided is not a function');
  }

  if (true === AdapterJS.onwebrtcreadyDone) {
    // All WebRTC interfaces are ready, just call the callback
    callback(null !== AdapterJS.WebRTCPlugin.plugin);
  } else {
    // will be triggered automatically when your browser/plugin is ready.
    AdapterJS._onwebrtcreadies.push(callback);
  }
};

// Plugin namespace
AdapterJS.WebRTCPlugin = AdapterJS.WebRTCPlugin || {};

// The object to store plugin information
/* jshint ignore:start */
AdapterJS.WebRTCPlugin.pluginInfo = AdapterJS.WebRTCPlugin.pluginInfo || {
  prefix : 'Tem',
  plugName : 'TemWebRTCPlugin',
  pluginId : 'plugin0',
  type : 'application/x-temwebrtcplugin',
  onload : '__TemWebRTCReady0',
  portalLink : 'http://skylink.io/plugin/',
  downloadLink : null, //set below
  companyName: 'Temasys',
  downloadLinks : {
    mac: 'http://bit.ly/webrtcpluginpkg',
    win: 'http://bit.ly/webrtcpluginmsi'
  }
};
if(typeof AdapterJS.WebRTCPlugin.pluginInfo.downloadLinks !== "undefined" && AdapterJS.WebRTCPlugin.pluginInfo.downloadLinks !== null) {
  if(!!navigator.platform.match(/^Mac/i)) {
    AdapterJS.WebRTCPlugin.pluginInfo.downloadLink = AdapterJS.WebRTCPlugin.pluginInfo.downloadLinks.mac;
  }
  else if(!!navigator.platform.match(/^Win/i)) {
    AdapterJS.WebRTCPlugin.pluginInfo.downloadLink = AdapterJS.WebRTCPlugin.pluginInfo.downloadLinks.win;
  }
}

/* jshint ignore:end */

AdapterJS.WebRTCPlugin.TAGS = {
  NONE  : 'none',
  AUDIO : 'audio',
  VIDEO : 'video'
};

// Unique identifier of each opened page
AdapterJS.WebRTCPlugin.pageId = Math.random().toString(36).slice(2);

// Use this whenever you want to call the plugin.
AdapterJS.WebRTCPlugin.plugin = null;

// Set log level for the plugin once it is ready.
// The different values are
// This is an asynchronous function that will run when the plugin is ready
AdapterJS.WebRTCPlugin.setLogLevel = null;

// Defines webrtc's JS interface according to the plugin's implementation.
// Define plugin Browsers as WebRTC Interface.
AdapterJS.WebRTCPlugin.defineWebRTCInterface = null;

// This function detects whether or not a plugin is installed.
// Checks if Not IE (firefox, for example), else if it's IE,
// we're running IE and do something. If not it is not supported.
AdapterJS.WebRTCPlugin.isPluginInstalled = null;

 // Lets adapter.js wait until the the document is ready before injecting the plugin
AdapterJS.WebRTCPlugin.pluginInjectionInterval = null;

// Inject the HTML DOM object element into the page.
AdapterJS.WebRTCPlugin.injectPlugin = null;

// States of readiness that the plugin goes through when
// being injected and stated
AdapterJS.WebRTCPlugin.PLUGIN_STATES = {
  NONE : 0,           // no plugin use
  INITIALIZING : 1,   // Detected need for plugin
  INJECTING : 2,      // Injecting plugin
  INJECTED: 3,        // Plugin element injected but not usable yet
  READY: 4            // Plugin ready to be used
};

// Current state of the plugin. You cannot use the plugin before this is
// equal to AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY
AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.NONE;

// True is AdapterJS.onwebrtcready was already called, false otherwise
// Used to make sure AdapterJS.onwebrtcready is only called once
AdapterJS.onwebrtcreadyDone = false;

// Log levels for the plugin.
// To be set by calling AdapterJS.WebRTCPlugin.setLogLevel
/*
Log outputs are prefixed in some cases.
  INFO: Information reported by the plugin.
  ERROR: Errors originating from within the plugin.
  WEBRTC: Error originating from within the libWebRTC library
*/
// From the least verbose to the most verbose
AdapterJS.WebRTCPlugin.PLUGIN_LOG_LEVELS = {
  NONE : 'NONE',
  ERROR : 'ERROR',
  WARNING : 'WARNING',
  INFO: 'INFO',
  VERBOSE: 'VERBOSE',
  SENSITIVE: 'SENSITIVE'
};

// Does a waiting check before proceeding to load the plugin.
AdapterJS.WebRTCPlugin.WaitForPluginReady = null;

// This methid will use an interval to wait for the plugin to be ready.
AdapterJS.WebRTCPlugin.callWhenPluginReady = null;

// !!!! WARNING: DO NOT OVERRIDE THIS FUNCTION. !!!
// This function will be called when plugin is ready. It sends necessary
// details to the plugin.
// The function will wait for the document to be ready and the set the
// plugin state to AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY,
// indicating that it can start being requested.
// This function is not in the IE/Safari condition brackets so that
// TemPluginLoaded function might be called on Chrome/Firefox.
// This function is the only private function that is not encapsulated to
// allow the plugin method to be called.
__TemWebRTCReady0 = function () {
  if (document.readyState === 'complete') {
    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY;
    AdapterJS.maybeThroughWebRTCReady();
  } else {
    var timer = setInterval(function () {
      if (document.readyState === 'complete') {
        // TODO: update comments, we wait for the document to be ready
        clearInterval(timer);
        AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY;
        AdapterJS.maybeThroughWebRTCReady();
      }
    }, 100);
  }
};

AdapterJS.maybeThroughWebRTCReady = function() {
  if (!AdapterJS.onwebrtcreadyDone) {
    AdapterJS.onwebrtcreadyDone = true;

    // If new interface for multiple callbacks used
    if (AdapterJS._onwebrtcreadies.length) {
      AdapterJS._onwebrtcreadies.forEach(function (callback) {
        if (typeof(callback) === 'function') {
          callback(AdapterJS.WebRTCPlugin.plugin !== null);
        }
      });
    // Else if no callbacks on new interface assuming user used old(deprecated) way to set callback through AdapterJS.onwebrtcready = ...
    } else if (typeof(AdapterJS.onwebrtcready) === 'function') {
      AdapterJS.onwebrtcready(AdapterJS.WebRTCPlugin.plugin !== null);
    }
  }
};

// Text namespace
AdapterJS.TEXT = {
  PLUGIN: {
    REQUIRE_INSTALLATION: 'This website requires you to install a WebRTC-enabling plugin ' +
      'to work on this browser.',
    NOT_SUPPORTED: 'Your browser does not support WebRTC.',
    BUTTON: 'Install Now'
  },
  REFRESH: {
    REQUIRE_REFRESH: 'Please refresh page',
    BUTTON: 'Refresh Page'
  }
};

// The result of ice connection states.
// - starting: Ice connection is starting.
// - checking: Ice connection is checking.
// - connected Ice connection is connected.
// - completed Ice connection is connected.
// - done Ice connection has been completed.
// - disconnected Ice connection has been disconnected.
// - failed Ice connection has failed.
// - closed Ice connection is closed.
AdapterJS._iceConnectionStates = {
  starting : 'starting',
  checking : 'checking',
  connected : 'connected',
  completed : 'connected',
  done : 'completed',
  disconnected : 'disconnected',
  failed : 'failed',
  closed : 'closed'
};

//The IceConnection states that has been fired for each peer.
AdapterJS._iceConnectionFiredStates = [];


// Check if WebRTC Interface is defined.
AdapterJS.isDefined = null;

// This function helps to retrieve the webrtc detected browser information.
// This sets:
// - webrtcDetectedBrowser: The browser agent name.
// - webrtcDetectedVersion: The browser version.
// - webrtcMinimumVersion: The minimum browser version still supported by AJS.
// - webrtcDetectedType: The types of webRTC support.
//   - 'moz': Mozilla implementation of webRTC.
//   - 'webkit': WebKit implementation of webRTC.
//   - 'plugin': Using the plugin implementation.
AdapterJS.parseWebrtcDetectedBrowser = function () {
  var hasMatch = null;

  // Detect Opera (8.0+)
  if ((!!window.opr && !!opr.addons) || !!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0) {
    hasMatch = navigator.userAgent.match(/OPR\/(\d+)/i) || [];

    webrtcDetectedBrowser   = 'opera';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 26;
    webrtcDetectedType      = 'webkit';
    webrtcDetectedDCSupport = 'SCTP'; // Opera 20+ uses Chrome 33

  // Detect Bowser on iOS
  } else if (navigator.userAgent.match(/Bowser\/[0-9.]*/g)) {
    hasMatch = navigator.userAgent.match(/Bowser\/[0-9.]*/g) || [];

    var chromiumVersion = parseInt((navigator.userAgent.match(/Chrom(e|ium)\/([0-9]+)\./i) || [])[2] || '0', 10);

    webrtcDetectedBrowser   = 'bowser';
    webrtcDetectedVersion   = parseFloat((hasMatch[0] || '0/0').split('/')[1], 10);
    webrtcMinimumVersion    = 0;
    webrtcDetectedType      = 'webkit';
    webrtcDetectedDCSupport = chromiumVersion > 30 ? 'SCTP' : 'RTP';


  // Detect Opera on iOS (does not support WebRTC yet)
  } else if (navigator.userAgent.indexOf('OPiOS') > 0) {
    hasMatch = navigator.userAgent.match(/OPiOS\/([0-9]+)\./);

    // Browser which do not support webrtc yet
    webrtcDetectedBrowser   = 'opera';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 0;
    webrtcDetectedType      = null;
    webrtcDetectedDCSupport = null;

  // Detect Chrome on iOS (does not support WebRTC yet)
  } else if (navigator.userAgent.indexOf('CriOS') > 0) {
    hasMatch = navigator.userAgent.match(/CriOS\/([0-9]+)\./) || [];

    webrtcDetectedBrowser   = 'chrome';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 0;
    webrtcDetectedType      = null;
    webrtcDetectedDCSupport = null;

  // Detect Firefox on iOS (does not support WebRTC yet)
  } else if (navigator.userAgent.indexOf('FxiOS') > 0) {
    hasMatch = navigator.userAgent.match(/FxiOS\/([0-9]+)\./) || [];

    // Browser which do not support webrtc yet
    webrtcDetectedBrowser   = 'firefox';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 0;
    webrtcDetectedType      = null;
    webrtcDetectedDCSupport = null;

  // Detect IE (6-11)
  } else if (/*@cc_on!@*/false || !!document.documentMode) {
    hasMatch = /\brv[ :]+(\d+)/g.exec(navigator.userAgent) || [];

    webrtcDetectedBrowser   = 'IE';
    webrtcDetectedVersion   = parseInt(hasMatch[1], 10);
    webrtcMinimumVersion    = 9;
    webrtcDetectedType      = 'plugin';
    webrtcDetectedDCSupport = 'SCTP';

    if (!webrtcDetectedVersion) {
      hasMatch = /\bMSIE[ :]+(\d+)/g.exec(navigator.userAgent) || [];

      webrtcDetectedVersion = parseInt(hasMatch[1] || '0', 10);
    }

  // Detect Edge (20+)
  } else if (!!window.StyleMedia || navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) {
    hasMatch = navigator.userAgent.match(/Edge\/(\d+).(\d+)$/) || [];

    // Previous webrtc/adapter uses minimum version as 10547 but checking in the Edge release history,
    // It's close to 13.10547 and ObjectRTC API is fully supported in that version

    webrtcDetectedBrowser   = 'edge';
    webrtcDetectedVersion   = parseFloat((hasMatch[0] || '0/0').split('/')[1], 10);
    webrtcMinimumVersion    = 13.10547;
    webrtcDetectedType      = 'ms';
    webrtcDetectedDCSupport = null;

  // Detect Firefox (1.0+)
  // Placed before Safari check to ensure Firefox on Android is detected
  } else if (typeof InstallTrigger !== 'undefined' || navigator.userAgent.indexOf('irefox') > 0) {
    hasMatch = navigator.userAgent.match(/Firefox\/([0-9]+)\./) || [];

    webrtcDetectedBrowser   = 'firefox';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 31;
    webrtcDetectedType      = 'moz';
    webrtcDetectedDCSupport = 'SCTP';

  // Detect Chrome (1+ and mobile)
  // Placed before Safari check to ensure Chrome on Android is detected
  } else if ((!!window.chrome && !!window.chrome.webstore) || navigator.userAgent.indexOf('Chrom') > 0) {
    hasMatch = navigator.userAgent.match(/Chrom(e|ium)\/([0-9]+)\./i) || [];

    webrtcDetectedBrowser   = 'chrome';
    webrtcDetectedVersion   = parseInt(hasMatch[2] || '0', 10);
    webrtcMinimumVersion    = 38;
    webrtcDetectedType      = 'webkit';
    webrtcDetectedDCSupport = webrtcDetectedVersion > 30 ? 'SCTP' : 'RTP'; // Chrome 31+ supports SCTP without flags

  // Detect Safari
  } else if (/^((?!chrome|android).)*safari/i.test(navigator.userAgent)) {
    hasMatch = navigator.userAgent.match(/version\/(\d+)/i) || [];

    var isMobile = navigator.userAgent.match(/(iPhone|iPad)/gi) || [];

    webrtcDetectedBrowser   = 'safari';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 7;
    webrtcDetectedType      = isMobile.length === 0 ? 'plugin' : null;
    webrtcDetectedDCSupport = isMobile.length === 0 ? 'SCTP' : null;

  // Detect WebView on iOS (does not support WebRTC yet)
  } else if (/(iPhone|iPod|iPad).*AppleWebKit(?!.*Safari)/i.test(navigator.userAgent)) {
    hasMatch = navigator.userAgent.match(/AppleWebKit\/([0-9]+)\./) || [];

    webrtcDetectedBrowser   = 'safari';
    webrtcDetectedVersion   = parseInt(hasMatch[1] || '0', 10);
    webrtcMinimumVersion    = 0;
    webrtcDetectedType      = null;
    webrtcDetectedDCSupport = null;

  }

  window.webrtcDetectedBrowser   = webrtcDetectedBrowser;
  window.webrtcDetectedVersion   = webrtcDetectedVersion;
  window.webrtcMinimumVersion    = webrtcMinimumVersion;
  window.webrtcDetectedType      = webrtcDetectedType; // Scope it to window for better consistency
  window.webrtcDetectedDCSupport = webrtcDetectedDCSupport; // Scope it to window for better consistency
};

AdapterJS.addEvent = function(elem, evnt, func) {
  if (elem.addEventListener) { // W3C DOM
    elem.addEventListener(evnt, func, false);
  } else if (elem.attachEvent) {// OLD IE DOM
    elem.attachEvent('on'+evnt, func);
  } else { // No much to do
    elem[evnt] = func;
  }
};

AdapterJS.renderNotificationBar = function (text, buttonText, buttonLink, openNewTab, displayRefreshBar) {
  // only inject once the page is ready
  if (document.readyState !== 'complete') {
    return;
  }

  var w = window;
  var i = document.createElement('iframe');
  i.name = 'adapterjs-alert';
  i.style.position = 'fixed';
  i.style.top = '-41px';
  i.style.left = 0;
  i.style.right = 0;
  i.style.width = '100%';
  i.style.height = '40px';
  i.style.backgroundColor = '#ffffe1';
  i.style.border = 'none';
  i.style.borderBottom = '1px solid #888888';
  i.style.zIndex = '9999999';
  if(typeof i.style.webkitTransition === 'string') {
    i.style.webkitTransition = 'all .5s ease-out';
  } else if(typeof i.style.transition === 'string') {
    i.style.transition = 'all .5s ease-out';
  }
  document.body.appendChild(i);
  var c = (i.contentWindow) ? i.contentWindow :
    (i.contentDocument.document) ? i.contentDocument.document : i.contentDocument;
  c.document.open();
  c.document.write('<span style="display: inline-block; font-family: Helvetica, Arial,' +
    'sans-serif; font-size: .9rem; padding: 4px; vertical-align: ' +
    'middle; cursor: default;">' + text + '</span>');
  if(buttonText && buttonLink) {
    c.document.write('<button id="okay">' + buttonText + '</button><button id="cancel">Cancel</button>');
    c.document.close();

    // On click on okay
    AdapterJS.addEvent(c.document.getElementById('okay'), 'click', function(e) {
      if (!!displayRefreshBar) {
        AdapterJS.renderNotificationBar(AdapterJS.TEXT.EXTENSION ?
          AdapterJS.TEXT.EXTENSION.REQUIRE_REFRESH : AdapterJS.TEXT.REFRESH.REQUIRE_REFRESH,
          AdapterJS.TEXT.REFRESH.BUTTON, 'javascript:location.reload()'); // jshint ignore:line
      }
      window.open(buttonLink, !!openNewTab ? '_blank' : '_top');

      e.preventDefault();
      try {
        e.cancelBubble = true;
      } catch(error) { }

      var pluginInstallInterval = setInterval(function(){
        if(! isIE) {
          navigator.plugins.refresh(false);
        }
        AdapterJS.WebRTCPlugin.isPluginInstalled(
          AdapterJS.WebRTCPlugin.pluginInfo.prefix,
          AdapterJS.WebRTCPlugin.pluginInfo.plugName,
          AdapterJS.WebRTCPlugin.pluginInfo.type,
          function() { // plugin now installed
            clearInterval(pluginInstallInterval);
            AdapterJS.WebRTCPlugin.defineWebRTCInterface();
          },
          function() {
            // still no plugin detected, nothing to do
          });
      } , 500);
    });

    // On click on Cancel
    AdapterJS.addEvent(c.document.getElementById('cancel'), 'click', function(e) {
      w.document.body.removeChild(i);
    });
  } else {
    c.document.close();
  }
  setTimeout(function() {
    if(typeof i.style.webkitTransform === 'string') {
      i.style.webkitTransform = 'translateY(40px)';
    } else if(typeof i.style.transform === 'string') {
      i.style.transform = 'translateY(40px)';
    } else {
      i.style.top = '0px';
    }
  }, 300);
};

// -----------------------------------------------------------
// Detected webrtc implementation. Types are:
// - 'moz': Mozilla implementation of webRTC.
// - 'webkit': WebKit implementation of webRTC.
// - 'plugin': Using the plugin implementation.
webrtcDetectedType = null;

// Set the settings for creating DataChannels, MediaStream for
// Cross-browser compability.
// - This is only for SCTP based support browsers.
// the 'urls' attribute.
checkMediaDataChannelSettings =
  function (peerBrowserAgent, peerBrowserVersion, callback, constraints) {
  if (typeof callback !== 'function') {
    return;
  }
  var beOfferer = true;
  var isLocalFirefox = webrtcDetectedBrowser === 'firefox';
  // Nightly version does not require MozDontOfferDataChannel for interop
  var isLocalFirefoxInterop = webrtcDetectedType === 'moz' && webrtcDetectedVersion > 30;
  var isPeerFirefox = peerBrowserAgent === 'firefox';
  var isPeerFirefoxInterop = peerBrowserAgent === 'firefox' &&
    ((peerBrowserVersion) ? (peerBrowserVersion > 30) : false);

  // Resends an updated version of constraints for MozDataChannel to work
  // If other userAgent is firefox and user is firefox, remove MozDataChannel
  if ((isLocalFirefox && isPeerFirefox) || (isLocalFirefoxInterop)) {
    try {
      delete constraints.mandatory.MozDontOfferDataChannel;
    } catch (error) {
      console.error('Failed deleting MozDontOfferDataChannel');
      console.error(error);
    }
  } else if ((isLocalFirefox && !isPeerFirefox)) {
    constraints.mandatory.MozDontOfferDataChannel = true;
  }
  if (!isLocalFirefox) {
    // temporary measure to remove Moz* constraints in non Firefox browsers
    for (var prop in constraints.mandatory) {
      if (constraints.mandatory.hasOwnProperty(prop)) {
        if (prop.indexOf('Moz') !== -1) {
          delete constraints.mandatory[prop];
        }
      }
    }
  }
  // Firefox (not interopable) cannot offer DataChannel as it will cause problems to the
  // interopability of the media stream
  if (isLocalFirefox && !isPeerFirefox && !isLocalFirefoxInterop) {
    beOfferer = false;
  }
  callback(beOfferer, constraints);
};

// Handles the differences for all browsers ice connection state output.
// - Tested outcomes are:
//   - Chrome (offerer)  : 'checking' > 'completed' > 'completed'
//   - Chrome (answerer) : 'checking' > 'connected'
//   - Firefox (offerer) : 'checking' > 'connected'
//   - Firefox (answerer): 'checking' > 'connected'
checkIceConnectionState = function (peerId, iceConnectionState, callback) {
  if (typeof callback !== 'function') {
    console.warn('No callback specified in checkIceConnectionState. Aborted.');
    return;
  }
  peerId = (peerId) ? peerId : 'peer';

  if (!AdapterJS._iceConnectionFiredStates[peerId] ||
    iceConnectionState === AdapterJS._iceConnectionStates.disconnected ||
    iceConnectionState === AdapterJS._iceConnectionStates.failed ||
    iceConnectionState === AdapterJS._iceConnectionStates.closed) {
    AdapterJS._iceConnectionFiredStates[peerId] = [];
  }
  iceConnectionState = AdapterJS._iceConnectionStates[iceConnectionState];
  if (AdapterJS._iceConnectionFiredStates[peerId].indexOf(iceConnectionState) < 0) {
    AdapterJS._iceConnectionFiredStates[peerId].push(iceConnectionState);
    if (iceConnectionState === AdapterJS._iceConnectionStates.connected) {
      setTimeout(function () {
        AdapterJS._iceConnectionFiredStates[peerId]
          .push(AdapterJS._iceConnectionStates.done);
        callback(AdapterJS._iceConnectionStates.done);
      }, 1000);
    }
    callback(iceConnectionState);
  }
  return;
};

// Firefox:
// - Creates iceServer from the url for Firefox.
// - Create iceServer with stun url.
// - Create iceServer with turn url.
//   - Ignore the transport parameter from TURN url for FF version <=27.
//   - Return null for createIceServer if transport=tcp.
// - FF 27 and above supports transport parameters in TURN url,
// - So passing in the full url to create iceServer.
// Chrome:
// - Creates iceServer from the url for Chrome M33 and earlier.
//   - Create iceServer with stun url.
//   - Chrome M28 & above uses below TURN format.
// Plugin:
// - Creates Ice Server for Plugin Browsers
//   - If Stun - Create iceServer with stun url.
//   - Else - Create iceServer with turn url
//   - This is a WebRTC Function
createIceServer = null;

// Firefox:
// - Creates IceServers for Firefox
//   - Use .url for FireFox.
//   - Multiple Urls support
// Chrome:
// - Creates iceServers from the urls for Chrome M34 and above.
//   - .urls is supported since Chrome M34.
//   - Multiple Urls support
// Plugin:
// - Creates Ice Servers for Plugin Browsers
//   - Multiple Urls support
//   - This is a WebRTC Function
createIceServers = null;
//------------------------------------------------------------

//The RTCPeerConnection object.
RTCPeerConnection = null;

// Creates RTCSessionDescription object for Plugin Browsers
RTCSessionDescription = (typeof RTCSessionDescription === 'function') ?
  RTCSessionDescription : null;

// Creates RTCIceCandidate object for Plugin Browsers
RTCIceCandidate = (typeof RTCIceCandidate === 'function') ?
  RTCIceCandidate : null;

// Get UserMedia (only difference is the prefix).
// Code from Adam Barth.
getUserMedia = null;

// Attach a media stream to an element.
attachMediaStream = null;

// Re-attach a media stream to an element.
reattachMediaStream = null;


// Detected browser agent name. Types are:
// - 'firefox': Firefox browser.
// - 'chrome': Chrome browser.
// - 'opera': Opera browser.
// - 'safari': Safari browser.
// - 'IE' - Internet Explorer browser.
webrtcDetectedBrowser = null;

// Detected browser version.
webrtcDetectedVersion = null;

// The minimum browser version still supported by AJS.
webrtcMinimumVersion  = null;

// Check for browser types and react accordingly
if ( (navigator.mozGetUserMedia ||
      navigator.webkitGetUserMedia ||
      (navigator.mediaDevices &&
       navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)))
    && !((navigator.userAgent.match(/android/ig) || []).length === 0 &&
          (navigator.userAgent.match(/chrome/ig) || []).length === 0 && navigator.userAgent.indexOf('Safari/') > 0)) {

  ///////////////////////////////////////////////////////////////////
  // INJECTION OF GOOGLE'S ADAPTER.JS CONTENT

/* jshint ignore:start */
  (function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.adapter = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
   /* eslint-env node */
  'use strict';

  // SDP helpers.
  var SDPUtils = {};

  // Generate an alphanumeric identifier for cname or mids.
  // TODO: use UUIDs instead? https://gist.github.com/jed/982883
  SDPUtils.generateIdentifier = function() {
    return Math.random().toString(36).substr(2, 10);
  };

  // The RTCP CNAME used by all peerconnections from the same JS.
  SDPUtils.localCName = SDPUtils.generateIdentifier();

  // Splits SDP into lines, dealing with both CRLF and LF.
  SDPUtils.splitLines = function(blob) {
    return blob.trim().split('\n').map(function(line) {
      return line.trim();
    });
  };
  // Splits SDP into sessionpart and mediasections. Ensures CRLF.
  SDPUtils.splitSections = function(blob) {
    var parts = blob.split('\nm=');
    return parts.map(function(part, index) {
      return (index > 0 ? 'm=' + part : part).trim() + '\r\n';
    });
  };

  // Returns lines that start with a certain prefix.
  SDPUtils.matchPrefix = function(blob, prefix) {
    return SDPUtils.splitLines(blob).filter(function(line) {
      return line.indexOf(prefix) === 0;
    });
  };

  // Parses an ICE candidate line. Sample input:
  // candidate:702786350 2 udp 41819902 8.8.8.8 60769 typ relay raddr 8.8.8.8
  // rport 55996"
  SDPUtils.parseCandidate = function(line) {
    var parts;
    // Parse both variants.
    if (line.indexOf('a=candidate:') === 0) {
      parts = line.substring(12).split(' ');
    } else {
      parts = line.substring(10).split(' ');
    }

    var candidate = {
      foundation: parts[0],
      component: parts[1],
      protocol: parts[2].toLowerCase(),
      priority: parseInt(parts[3], 10),
      ip: parts[4],
      port: parseInt(parts[5], 10),
      // skip parts[6] == 'typ'
      type: parts[7]
    };

    for (var i = 8; i < parts.length; i += 2) {
      switch (parts[i]) {
        case 'raddr':
          candidate.relatedAddress = parts[i + 1];
          break;
        case 'rport':
          candidate.relatedPort = parseInt(parts[i + 1], 10);
          break;
        case 'tcptype':
          candidate.tcpType = parts[i + 1];
          break;
        default: // Unknown extensions are silently ignored.
          break;
      }
    }
    return candidate;
  };

  // Translates a candidate object into SDP candidate attribute.
  SDPUtils.writeCandidate = function(candidate) {
    var sdp = [];
    sdp.push(candidate.foundation);
    sdp.push(candidate.component);
    sdp.push(candidate.protocol.toUpperCase());
    sdp.push(candidate.priority);
    sdp.push(candidate.ip);
    sdp.push(candidate.port);

    var type = candidate.type;
    sdp.push('typ');
    sdp.push(type);
    if (type !== 'host' && candidate.relatedAddress &&
        candidate.relatedPort) {
      sdp.push('raddr');
      sdp.push(candidate.relatedAddress); // was: relAddr
      sdp.push('rport');
      sdp.push(candidate.relatedPort); // was: relPort
    }
    if (candidate.tcpType && candidate.protocol.toLowerCase() === 'tcp') {
      sdp.push('tcptype');
      sdp.push(candidate.tcpType);
    }
    return 'candidate:' + sdp.join(' ');
  };

  // Parses an rtpmap line, returns RTCRtpCoddecParameters. Sample input:
  // a=rtpmap:111 opus/48000/2
  SDPUtils.parseRtpMap = function(line) {
    var parts = line.substr(9).split(' ');
    var parsed = {
      payloadType: parseInt(parts.shift(), 10) // was: id
    };

    parts = parts[0].split('/');

    parsed.name = parts[0];
    parsed.clockRate = parseInt(parts[1], 10); // was: clockrate
    // was: channels
    parsed.numChannels = parts.length === 3 ? parseInt(parts[2], 10) : 1;
    return parsed;
  };

  // Generate an a=rtpmap line from RTCRtpCodecCapability or
  // RTCRtpCodecParameters.
  SDPUtils.writeRtpMap = function(codec) {
    var pt = codec.payloadType;
    if (codec.preferredPayloadType !== undefined) {
      pt = codec.preferredPayloadType;
    }
    return 'a=rtpmap:' + pt + ' ' + codec.name + '/' + codec.clockRate +
        (codec.numChannels !== 1 ? '/' + codec.numChannels : '') + '\r\n';
  };

  // Parses an a=extmap line (headerextension from RFC 5285). Sample input:
  // a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
  SDPUtils.parseExtmap = function(line) {
    var parts = line.substr(9).split(' ');
    return {
      id: parseInt(parts[0], 10),
      uri: parts[1]
    };
  };

  // Generates a=extmap line from RTCRtpHeaderExtensionParameters or
  // RTCRtpHeaderExtension.
  SDPUtils.writeExtmap = function(headerExtension) {
    return 'a=extmap:' + (headerExtension.id || headerExtension.preferredId) +
         ' ' + headerExtension.uri + '\r\n';
  };

  // Parses an ftmp line, returns dictionary. Sample input:
  // a=fmtp:96 vbr=on;cng=on
  // Also deals with vbr=on; cng=on
  SDPUtils.parseFmtp = function(line) {
    var parsed = {};
    var kv;
    var parts = line.substr(line.indexOf(' ') + 1).split(';');
    for (var j = 0; j < parts.length; j++) {
      kv = parts[j].trim().split('=');
      parsed[kv[0].trim()] = kv[1];
    }
    return parsed;
  };

  // Generates an a=ftmp line from RTCRtpCodecCapability or RTCRtpCodecParameters.
  SDPUtils.writeFmtp = function(codec) {
    var line = '';
    var pt = codec.payloadType;
    if (codec.preferredPayloadType !== undefined) {
      pt = codec.preferredPayloadType;
    }
    if (codec.parameters && Object.keys(codec.parameters).length) {
      var params = [];
      Object.keys(codec.parameters).forEach(function(param) {
        params.push(param + '=' + codec.parameters[param]);
      });
      line += 'a=fmtp:' + pt + ' ' + params.join(';') + '\r\n';
    }
    return line;
  };

  // Parses an rtcp-fb line, returns RTCPRtcpFeedback object. Sample input:
  // a=rtcp-fb:98 nack rpsi
  SDPUtils.parseRtcpFb = function(line) {
    var parts = line.substr(line.indexOf(' ') + 1).split(' ');
    return {
      type: parts.shift(),
      parameter: parts.join(' ')
    };
  };
  // Generate a=rtcp-fb lines from RTCRtpCodecCapability or RTCRtpCodecParameters.
  SDPUtils.writeRtcpFb = function(codec) {
    var lines = '';
    var pt = codec.payloadType;
    if (codec.preferredPayloadType !== undefined) {
      pt = codec.preferredPayloadType;
    }
    if (codec.rtcpFeedback && codec.rtcpFeedback.length) {
      // FIXME: special handling for trr-int?
      codec.rtcpFeedback.forEach(function(fb) {
        lines += 'a=rtcp-fb:' + pt + ' ' + fb.type +
        (fb.parameter && fb.parameter.length ? ' ' + fb.parameter : '') +
            '\r\n';
      });
    }
    return lines;
  };

  // Parses an RFC 5576 ssrc media attribute. Sample input:
  // a=ssrc:3735928559 cname:something
  SDPUtils.parseSsrcMedia = function(line) {
    var sp = line.indexOf(' ');
    var parts = {
      ssrc: parseInt(line.substr(7, sp - 7), 10)
    };
    var colon = line.indexOf(':', sp);
    if (colon > -1) {
      parts.attribute = line.substr(sp + 1, colon - sp - 1);
      parts.value = line.substr(colon + 1);
    } else {
      parts.attribute = line.substr(sp + 1);
    }
    return parts;
  };

  // Extracts DTLS parameters from SDP media section or sessionpart.
  // FIXME: for consistency with other functions this should only
  //   get the fingerprint line as input. See also getIceParameters.
  SDPUtils.getDtlsParameters = function(mediaSection, sessionpart) {
    var lines = SDPUtils.splitLines(mediaSection);
    // Search in session part, too.
    lines = lines.concat(SDPUtils.splitLines(sessionpart));
    var fpLine = lines.filter(function(line) {
      return line.indexOf('a=fingerprint:') === 0;
    })[0].substr(14);
    // Note: a=setup line is ignored since we use the 'auto' role.
    var dtlsParameters = {
      role: 'auto',
      fingerprints: [{
        algorithm: fpLine.split(' ')[0],
        value: fpLine.split(' ')[1]
      }]
    };
    return dtlsParameters;
  };

  // Serializes DTLS parameters to SDP.
  SDPUtils.writeDtlsParameters = function(params, setupType) {
    var sdp = 'a=setup:' + setupType + '\r\n';
    params.fingerprints.forEach(function(fp) {
      sdp += 'a=fingerprint:' + fp.algorithm + ' ' + fp.value + '\r\n';
    });
    return sdp;
  };
  // Parses ICE information from SDP media section or sessionpart.
  // FIXME: for consistency with other functions this should only
  //   get the ice-ufrag and ice-pwd lines as input.
  SDPUtils.getIceParameters = function(mediaSection, sessionpart) {
    var lines = SDPUtils.splitLines(mediaSection);
    // Search in session part, too.
    lines = lines.concat(SDPUtils.splitLines(sessionpart));
    var iceParameters = {
      usernameFragment: lines.filter(function(line) {
        return line.indexOf('a=ice-ufrag:') === 0;
      })[0].substr(12),
      password: lines.filter(function(line) {
        return line.indexOf('a=ice-pwd:') === 0;
      })[0].substr(10)
    };
    return iceParameters;
  };

  // Serializes ICE parameters to SDP.
  SDPUtils.writeIceParameters = function(params) {
    return 'a=ice-ufrag:' + params.usernameFragment + '\r\n' +
        'a=ice-pwd:' + params.password + '\r\n';
  };

  // Parses the SDP media section and returns RTCRtpParameters.
  SDPUtils.parseRtpParameters = function(mediaSection) {
    var description = {
      codecs: [],
      headerExtensions: [],
      fecMechanisms: [],
      rtcp: []
    };
    var lines = SDPUtils.splitLines(mediaSection);
    var mline = lines[0].split(' ');
    for (var i = 3; i < mline.length; i++) { // find all codecs from mline[3..]
      var pt = mline[i];
      var rtpmapline = SDPUtils.matchPrefix(
          mediaSection, 'a=rtpmap:' + pt + ' ')[0];
      if (rtpmapline) {
        var codec = SDPUtils.parseRtpMap(rtpmapline);
        var fmtps = SDPUtils.matchPrefix(
            mediaSection, 'a=fmtp:' + pt + ' ');
        // Only the first a=fmtp:<pt> is considered.
        codec.parameters = fmtps.length ? SDPUtils.parseFmtp(fmtps[0]) : {};
        codec.rtcpFeedback = SDPUtils.matchPrefix(
            mediaSection, 'a=rtcp-fb:' + pt + ' ')
          .map(SDPUtils.parseRtcpFb);
        description.codecs.push(codec);
        // parse FEC mechanisms from rtpmap lines.
        switch (codec.name.toUpperCase()) {
          case 'RED':
          case 'ULPFEC':
            description.fecMechanisms.push(codec.name.toUpperCase());
            break;
          default: // only RED and ULPFEC are recognized as FEC mechanisms.
            break;
        }
      }
    }
    SDPUtils.matchPrefix(mediaSection, 'a=extmap:').forEach(function(line) {
      description.headerExtensions.push(SDPUtils.parseExtmap(line));
    });
    // FIXME: parse rtcp.
    return description;
  };

  // Generates parts of the SDP media section describing the capabilities /
  // parameters.
  SDPUtils.writeRtpDescription = function(kind, caps) {
    var sdp = '';

    // Build the mline.
    sdp += 'm=' + kind + ' ';
    sdp += caps.codecs.length > 0 ? '9' : '0'; // reject if no codecs.
    sdp += ' UDP/TLS/RTP/SAVPF ';
    sdp += caps.codecs.map(function(codec) {
      if (codec.preferredPayloadType !== undefined) {
        return codec.preferredPayloadType;
      }
      return codec.payloadType;
    }).join(' ') + '\r\n';

    sdp += 'c=IN IP4 0.0.0.0\r\n';
    sdp += 'a=rtcp:9 IN IP4 0.0.0.0\r\n';

    // Add a=rtpmap lines for each codec. Also fmtp and rtcp-fb.
    caps.codecs.forEach(function(codec) {
      sdp += SDPUtils.writeRtpMap(codec);
      sdp += SDPUtils.writeFmtp(codec);
      sdp += SDPUtils.writeRtcpFb(codec);
    });
    // FIXME: add headerExtensions, fecMechanismş and rtcp.
    sdp += 'a=rtcp-mux\r\n';
    return sdp;
  };

  // Parses the SDP media section and returns an array of
  // RTCRtpEncodingParameters.
  SDPUtils.parseRtpEncodingParameters = function(mediaSection) {
    var encodingParameters = [];
    var description = SDPUtils.parseRtpParameters(mediaSection);
    var hasRed = description.fecMechanisms.indexOf('RED') !== -1;
    var hasUlpfec = description.fecMechanisms.indexOf('ULPFEC') !== -1;

    // filter a=ssrc:... cname:, ignore PlanB-msid
    var ssrcs = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
    .map(function(line) {
      return SDPUtils.parseSsrcMedia(line);
    })
    .filter(function(parts) {
      return parts.attribute === 'cname';
    });
    var primarySsrc = ssrcs.length > 0 && ssrcs[0].ssrc;
    var secondarySsrc;

    var flows = SDPUtils.matchPrefix(mediaSection, 'a=ssrc-group:FID')
    .map(function(line) {
      var parts = line.split(' ');
      parts.shift();
      return parts.map(function(part) {
        return parseInt(part, 10);
      });
    });
    if (flows.length > 0 && flows[0].length > 1 && flows[0][0] === primarySsrc) {
      secondarySsrc = flows[0][1];
    }

    description.codecs.forEach(function(codec) {
      if (codec.name.toUpperCase() === 'RTX' && codec.parameters.apt) {
        var encParam = {
          ssrc: primarySsrc,
          codecPayloadType: parseInt(codec.parameters.apt, 10),
          rtx: {
            payloadType: codec.payloadType,
            ssrc: secondarySsrc
          }
        };
        encodingParameters.push(encParam);
        if (hasRed) {
          encParam = JSON.parse(JSON.stringify(encParam));
          encParam.fec = {
            ssrc: secondarySsrc,
            mechanism: hasUlpfec ? 'red+ulpfec' : 'red'
          };
          encodingParameters.push(encParam);
        }
      }
    });
    if (encodingParameters.length === 0 && primarySsrc) {
      encodingParameters.push({
        ssrc: primarySsrc
      });
    }

    // we support both b=AS and b=TIAS but interpret AS as TIAS.
    var bandwidth = SDPUtils.matchPrefix(mediaSection, 'b=');
    if (bandwidth.length) {
      if (bandwidth[0].indexOf('b=TIAS:') === 0) {
        bandwidth = parseInt(bandwidth[0].substr(7), 10);
      } else if (bandwidth[0].indexOf('b=AS:') === 0) {
        bandwidth = parseInt(bandwidth[0].substr(5), 10);
      }
      encodingParameters.forEach(function(params) {
        params.maxBitrate = bandwidth;
      });
    }
    return encodingParameters;
  };

  SDPUtils.writeSessionBoilerplate = function() {
    // FIXME: sess-id should be an NTP timestamp.
    return 'v=0\r\n' +
        'o=thisisadapterortc 8169639915646943137 2 IN IP4 127.0.0.1\r\n' +
        's=-\r\n' +
        't=0 0\r\n';
  };

  SDPUtils.writeMediaSection = function(transceiver, caps, type, stream) {
    var sdp = SDPUtils.writeRtpDescription(transceiver.kind, caps);

    // Map ICE parameters (ufrag, pwd) to SDP.
    sdp += SDPUtils.writeIceParameters(
        transceiver.iceGatherer.getLocalParameters());

    // Map DTLS parameters to SDP.
    sdp += SDPUtils.writeDtlsParameters(
        transceiver.dtlsTransport.getLocalParameters(),
        type === 'offer' ? 'actpass' : 'active');

    sdp += 'a=mid:' + transceiver.mid + '\r\n';

    if (transceiver.rtpSender && transceiver.rtpReceiver) {
      sdp += 'a=sendrecv\r\n';
    } else if (transceiver.rtpSender) {
      sdp += 'a=sendonly\r\n';
    } else if (transceiver.rtpReceiver) {
      sdp += 'a=recvonly\r\n';
    } else {
      sdp += 'a=inactive\r\n';
    }

    // FIXME: for RTX there might be multiple SSRCs. Not implemented in Edge yet.
    if (transceiver.rtpSender) {
      var msid = 'msid:' + stream.id + ' ' +
          transceiver.rtpSender.track.id + '\r\n';
      sdp += 'a=' + msid;
      sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
          ' ' + msid;
    }
    // FIXME: this should be written by writeRtpDescription.
    sdp += 'a=ssrc:' + transceiver.sendEncodingParameters[0].ssrc +
        ' cname:' + SDPUtils.localCName + '\r\n';
    return sdp;
  };

  // Gets the direction from the mediaSection or the sessionpart.
  SDPUtils.getDirection = function(mediaSection, sessionpart) {
    // Look for sendrecv, sendonly, recvonly, inactive, default to sendrecv.
    var lines = SDPUtils.splitLines(mediaSection);
    for (var i = 0; i < lines.length; i++) {
      switch (lines[i]) {
        case 'a=sendrecv':
        case 'a=sendonly':
        case 'a=recvonly':
        case 'a=inactive':
          return lines[i].substr(2);
        default:
          // FIXME: What should happen here?
      }
    }
    if (sessionpart) {
      return SDPUtils.getDirection(sessionpart);
    }
    return 'sendrecv';
  };

  // Expose public methods.
  module.exports = SDPUtils;

  },{}],2:[function(require,module,exports){
  /*
   *  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';

  // Shimming starts here.
  (function() {
    // Utils.
    var logging = require('./utils').log;
    var browserDetails = require('./utils').browserDetails;
    // Export to the adapter global object visible in the browser.
    module.exports.browserDetails = browserDetails;
    module.exports.extractVersion = require('./utils').extractVersion;
    module.exports.disableLog = require('./utils').disableLog;

    // Uncomment the line below if you want logging to occur, including logging
    // for the switch statement below. Can also be turned on in the browser via
    // adapter.disableLog(false), but then logging from the switch statement below
    // will not appear.
    // require('./utils').disableLog(false);

    // Browser shims.
    var chromeShim = require('./chrome/chrome_shim') || null;
    var edgeShim = require('./edge/edge_shim') || null;
    var firefoxShim = require('./firefox/firefox_shim') || null;
    var safariShim = require('./safari/safari_shim') || null;

    // Shim browser if found.
    switch (browserDetails.browser) {
      case 'opera': // fallthrough as it uses chrome shims
      case 'chrome':
        if (!chromeShim || !chromeShim.shimPeerConnection) {
          logging('Chrome shim is not included in this adapter release.');
          return;
        }
        logging('adapter.js shimming chrome.');
        // Export to the adapter global object visible in the browser.
        module.exports.browserShim = chromeShim;

        chromeShim.shimGetUserMedia();
        chromeShim.shimMediaStream();
        chromeShim.shimSourceObject();
        chromeShim.shimPeerConnection();
        chromeShim.shimOnTrack();
        break;
      case 'firefox':
        if (!firefoxShim || !firefoxShim.shimPeerConnection) {
          logging('Firefox shim is not included in this adapter release.');
          return;
        }
        logging('adapter.js shimming firefox.');
        // Export to the adapter global object visible in the browser.
        module.exports.browserShim = firefoxShim;

        firefoxShim.shimGetUserMedia();
        firefoxShim.shimSourceObject();
        firefoxShim.shimPeerConnection();
        firefoxShim.shimOnTrack();
        break;
      case 'edge':
        if (!edgeShim || !edgeShim.shimPeerConnection) {
          logging('MS edge shim is not included in this adapter release.');
          return;
        }
        logging('adapter.js shimming edge.');
        // Export to the adapter global object visible in the browser.
        module.exports.browserShim = edgeShim;

        edgeShim.shimGetUserMedia();
        edgeShim.shimPeerConnection();
        break;
      case 'safari':
        if (!safariShim) {
          logging('Safari shim is not included in this adapter release.');
          return;
        }
        logging('adapter.js shimming safari.');
        // Export to the adapter global object visible in the browser.
        module.exports.browserShim = safariShim;

        safariShim.shimGetUserMedia();
        break;
      default:
        logging('Unsupported browser!');
    }
  })();

  },{"./chrome/chrome_shim":3,"./edge/edge_shim":5,"./firefox/firefox_shim":7,"./safari/safari_shim":9,"./utils":10}],3:[function(require,module,exports){

  /*
   *  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 logging = require('../utils.js').log;
  var browserDetails = require('../utils.js').browserDetails;

  var chromeShim = {
    shimMediaStream: function() {
      window.MediaStream = window.MediaStream || window.webkitMediaStream;
    },

    shimOnTrack: function() {
      if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
          window.RTCPeerConnection.prototype)) {
        Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
          get: function() {
            return this._ontrack;
          },
          set: function(f) {
            var self = this;
            if (this._ontrack) {
              this.removeEventListener('track', this._ontrack);
              this.removeEventListener('addstream', this._ontrackpoly);
            }
            this.addEventListener('track', this._ontrack = f);
            this.addEventListener('addstream', 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 event = new Event('track');
                event.track = te.track;
                event.receiver = {track: te.track};
                event.streams = [e.stream];
                self.dispatchEvent(event);
              });
              e.stream.getTracks().forEach(function(track) {
                var event = new Event('track');
                event.track = track;
                event.receiver = {track: track};
                event.streams = [e.stream];
                this.dispatchEvent(event);
              }.bind(this));
            }.bind(this));
          }
        });
      }
    },

    shimSourceObject: function() {
      if (typeof window === 'object') {
        if (window.HTMLMediaElement &&
          !('srcObject' in window.HTMLMediaElement.prototype)) {
          // Shim the srcObject property, once, when HTMLMediaElement is found.
          Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
            get: function() {
              return this._srcObject;
            },
            set: function(stream) {
              var self = this;
              // Use _srcObject as a private property for this shim
              this._srcObject = stream;
              if (this.src) {
                URL.revokeObjectURL(this.src);
              }

              if (!stream) {
                this.src = '';
                return;
              }
              this.src = URL.createObjectURL(stream);
              // We need to recreate the blob url when a track is added or
              // removed. Doing it manually since we want to avoid a recursion.
              stream.addEventListener('addtrack', function() {
                if (self.src) {
                  URL.revokeObjectURL(self.src);
                }
                self.src = URL.createObjectURL(stream);
              });
              stream.addEventListener('removetrack', function() {
                if (self.src) {
                  URL.revokeObjectURL(self.src);
                }
                self.src = URL.createObjectURL(stream);
              });
            }
          });
        }
      }
    },

    shimPeerConnection: function() {
      // The RTCPeerConnection object.
      window.RTCPeerConnection = function(pcConfig, pcConstraints) {
        // Translate iceTransportPolicy to iceTransports,
        // see https://code.google.com/p/webrtc/issues/detail?id=4869
        logging('PeerConnection');
        if (pcConfig && pcConfig.iceTransportPolicy) {
          pcConfig.iceTransports = pcConfig.iceTransportPolicy;
        }

        var pc = new webkitRTCPeerConnection(pcConfig, pcConstraints);
        var origGetStats = pc.getStats.bind(pc);
        pc.getStats = function(selector, successCallback, errorCallback) {
          var self = this;
          var args = arguments;

          // If selector is a function then we are in the old style stats so just
          // pass back the original getStats format to avoid breaking old users.
          if (arguments.length > 0 && typeof selector === 'function') {
            return origGetStats(selector, successCallback);
          }

          var fixChromeStats_ = function(response) {
            var standardReport = {};
            var reports = response.result();
            reports.forEach(function(report) {
              var standardStats = {
                id: report.id,
                timestamp: report.timestamp,
                type: report.type
              };
              report.names().forEach(function(name) {
                standardStats[name] = report.stat(name);
              });
              standardReport[standardStats.id] = standardStats;
            });

            return standardReport;
          };

          // shim getStats with maplike support
          var makeMapStats = function(stats, legacyStats) {
            var map = new Map(Object.keys(stats).map(function(key) {
              return[key, stats[key]];
            }));
            legacyStats = legacyStats || stats;
            Object.keys(legacyStats).forEach(function(key) {
              map[key] = legacyStats[key];
            });
            return map;
          };

          if (arguments.length >= 2) {
            var successCallbackWrapper_ = function(response) {
              args[1](makeMapStats(fixChromeStats_(response)));
            };

            return origGetStats.apply(this, [successCallbackWrapper_,
                arguments[0]]);
          }

          // promise-support
          return new Promise(function(resolve, reject) {
            if (args.length === 1 && typeof selector === 'object') {
              origGetStats.apply(self, [
                function(response) {
                  resolve(makeMapStats(fixChromeStats_(response)));
                }, reject]);
            } else {
              // Preserve legacy chrome stats only on legacy access of stats obj
              origGetStats.apply(self, [
                function(response) {
                  resolve(makeMapStats(fixChromeStats_(response),
                      response.result()));
                }, reject]);
            }
          }).then(successCallback, errorCallback);
        };

        return pc;
      };
      window.RTCPeerConnection.prototype = webkitRTCPeerConnection.prototype;

      // wrap static methods. Currently just generateCertificate.
      if (webkitRTCPeerConnection.generateCertificate) {
        Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
          get: function() {
            return webkitRTCPeerConnection.generateCertificate;
          }
        });
      }

      ['createOffer', 'createAnswer'].forEach(function(method) {
        var nativeMethod = webkitRTCPeerConnection.prototype[method];
        webkitRTCPeerConnection.prototype[method] = function() {
          var self = this;
          if (arguments.length < 1 || (arguments.length === 1 &&
              typeof arguments[0] === 'object')) {
            var opts = arguments.length === 1 ? arguments[0] : undefined;
            return new Promise(function(resolve, reject) {
              nativeMethod.apply(self, [resolve, reject, opts]);
            });
          }
          return nativeMethod.apply(this, arguments);
        };
      });

      // add promise support -- natively available in Chrome 51
      if (browserDetails.version < 51) {
        ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
            .forEach(function(method) {
              var nativeMethod = webkitRTCPeerConnection.prototype[method];
              webkitRTCPeerConnection.prototype[method] = function() {
                var args = arguments;
                var self = this;
                var promise = new Promise(function(resolve, reject) {
                  nativeMethod.apply(self, [args[0], resolve, reject]);
                });
                if (args.length < 2) {
                  return promise;
                }
                return promise.then(function() {
                  args[1].apply(null, []);
                },
                function(err) {
                  if (args.length >= 3) {
                    args[2].apply(null, [err]);
                  }
                });
              };
            });
      }

      // shim implicit creation of RTCSessionDescription/RTCIceCandidate
      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
          .forEach(function(method) {
            var nativeMethod = webkitRTCPeerConnection.prototype[method];
            webkitRTCPeerConnection.prototype[method] = function() {
              arguments[0] = new ((method === 'addIceCandidate') ?
                  RTCIceCandidate : RTCSessionDescription)(arguments[0]);
              return nativeMethod.apply(this, arguments);
            };
          });

      // support for addIceCandidate(null)
      var nativeAddIceCandidate =
          RTCPeerConnection.prototype.addIceCandidate;
      RTCPeerConnection.prototype.addIceCandidate = function() {
        return arguments[0] === null ? Promise.resolve()
            : nativeAddIceCandidate.apply(this, arguments);
      };
    }
  };


  // Expose public methods.
  module.exports = {
    shimMediaStream: chromeShim.shimMediaStream,
    shimOnTrack: chromeShim.shimOnTrack,
    shimSourceObject: chromeShim.shimSourceObject,
    shimPeerConnection: chromeShim.shimPeerConnection,
    shimGetUserMedia: require('./getusermedia')
  };

  },{"../utils.js":10,"./getusermedia":4}],4:[function(require,module,exports){
  /*
   *  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 logging = require('../utils.js').log;

  // Expose public methods.
  module.exports = function() {
    var constraintsToChrome_ = function(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(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(constraints, func) {
      constraints = JSON.parse(JSON.stringify(constraints));
      if (constraints && constraints.audio) {
        constraints.audio = constraintsToChrome_(constraints.audio);
      }
      if (constraints && typeof constraints.video === 'object') {
        // Shim facingMode for mobile, where it defaults to "user".
        var face = constraints.video.facingMode;
        face = face && ((typeof face === 'object') ? face : {ideal: face});

        if ((face && (face.exact === 'user' || face.exact === 'environment' ||
                      face.ideal === 'user' || face.ideal === 'environment')) &&
            !(navigator.mediaDevices.getSupportedConstraints &&
              navigator.mediaDevices.getSupportedConstraints().facingMode)) {
          delete constraints.video.facingMode;
          if (face.exact === 'environment' || face.ideal === 'environment') {
            // Look for "back" in label, or use last cam (typically back cam).
            return navigator.mediaDevices.enumerateDevices()
            .then(function(devices) {
              devices = devices.filter(function(d) {
                return d.kind === 'videoinput';
              });
              var back = devices.find(function(d) {
                return d.label.toLowerCase().indexOf('back') !== -1;
              }) || (devices.length && devices[devices.length - 1]);
              if (back) {
                constraints.video.deviceId = face.exact ? {exact: back.deviceId} :
                                                          {ideal: back.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(e) {
      return {
        name: {
          PermissionDeniedError: 'NotAllowedError',
          ConstraintNotSatisfiedError: 'OverconstrainedError'
        }[e.name] || e.name,
        message: e.message,
        constraint: e.constraintName,
        toString: function() {
          return this.name + (this.message && ': ') + this.message;
        }
      };
    };

    var getUserMedia_ = function(constraints, onSuccess, onError) {
      shimConstraints_(constraints, function(c) {
        navigator.webkitGetUserMedia(c, onSuccess, function(e) {
          onError(shimError_(e));
        });
      });
    };

    navigator.getUserMedia = getUserMedia_;

    // Returns the result of getUserMedia as a Promise.
    var getUserMediaPromise_ = function(constraints) {
      return new Promise(function(resolve, reject) {
        navigator.getUserMedia(constraints, resolve, reject);
      });
    };

    if (!navigator.mediaDevices) {
      navigator.mediaDevices = {
        getUserMedia: getUserMediaPromise_,
        enumerateDevices: function() {
          return new Promise(function(resolve) {
            var kinds = {audio: 'audioinput', video: 'videoinput'};
            return MediaStreamTrack.getSources(function(devices) {
              resolve(devices.map(function(device) {
                return {label: device.label,
                        kind: kinds[device.kind],
                        deviceId: device.id,
                        groupId: ''};
              }));
            });
          });
        }
      };
    }

    // A shim for getUserMedia method on the mediaDevices object.
    // TODO(KaptenJansson) remove once implemented in Chrome stable.
    if (!navigator.mediaDevices.getUserMedia) {
      navigator.mediaDevices.getUserMedia = function(constraints) {
        return getUserMediaPromise_(constraints);
      };
    } else {
      // Even though Chrome 45 has navigator.mediaDevices and a getUserMedia
      // function which returns a Promise, it does not accept spec-style
      // constraints.
      var origGetUserMedia = navigator.mediaDevices.getUserMedia.
          bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(cs) {
        return shimConstraints_(cs, function(c) {
          return origGetUserMedia(c).catch(function(e) {
            return Promise.reject(shimError_(e));
          });
        });
      };
    }

    // Dummy devicechange event methods.
    // TODO(KaptenJansson) remove once implemented in Chrome stable.
    if (typeof navigator.mediaDevices.addEventListener === 'undefined') {
      navigator.mediaDevices.addEventListener = function() {
        logging('Dummy mediaDevices.addEventListener called.');
      };
    }
    if (typeof navigator.mediaDevices.removeEventListener === 'undefined') {
      navigator.mediaDevices.removeEventListener = function() {
        logging('Dummy mediaDevices.removeEventListener called.');
      };
    }
  };

  },{"../utils.js":10}],5:[function(require,module,exports){
  /*
   *  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 SDPUtils = require('sdp');
  var browserDetails = require('../utils').browserDetails;

  var edgeShim = {
    shimPeerConnection: function() {
      if (window.RTCIceGatherer) {
        // ORTC defines an RTCIceCandidate object but no constructor.
        // Not implemented in Edge.
        if (!window.RTCIceCandidate) {
          window.RTCIceCandidate = function(args) {
            return args;
          };
        }
        // ORTC does not have a session description object but
        // other browsers (i.e. Chrome) that will support both PC and ORTC
        // in the future might have this defined already.
        if (!window.RTCSessionDescription) {
          window.RTCSessionDescription = function(args) {
            return args;
          };
        }
      }

      window.RTCPeerConnection = function(config) {
        var self = this;

        var _eventTarget = document.createDocumentFragment();
        ['addEventListener', 'removeEventListener', 'dispatchEvent']
            .forEach(function(method) {
              self[method] = _eventTarget[method].bind(_eventTarget);
            });

        this.onicecandidate = null;
        this.onaddstream = null;
        this.ontrack = null;
        this.onremovestream = null;
        this.onsignalingstatechange = null;
        this.oniceconnectionstatechange = null;
        this.onnegotiationneeded = null;
        this.ondatachannel = null;

        this.localStreams = [];
        this.remoteStreams = [];
        this.getLocalStreams = function() {
          return self.localStreams;
        };
        this.getRemoteStreams = function() {
          return self.remoteStreams;
        };

        this.localDescription = new RTCSessionDescription({
          type: '',
          sdp: ''
        });
        this.remoteDescription = new RTCSessionDescription({
          type: '',
          sdp: ''
        });
        this.signalingState = 'stable';
        this.iceConnectionState = 'new';
        this.iceGatheringState = 'new';

        this.iceOptions = {
          gatherPolicy: 'all',
          iceServers: []
        };
        if (config && config.iceTransportPolicy) {
          switch (config.iceTransportPolicy) {
            case 'all':
            case 'relay':
              this.iceOptions.gatherPolicy = config.iceTransportPolicy;
              break;
            case 'none':
              // FIXME: remove once implementation and spec have added this.
              throw new TypeError('iceTransportPolicy "none" not supported');
            default:
              // don't set iceTransportPolicy.
              break;
          }
        }
        this.usingBundle = config && config.bundlePolicy === 'max-bundle';

        if (config && config.iceServers) {
          // Edge does not like
          // 1) stun:
          // 2) turn: that does not have all of turn:host:port?transport=udp
          // 3) turn: with ipv6 addresses
          var iceServers = JSON.parse(JSON.stringify(config.iceServers));
          this.iceOptions.iceServers = iceServers.filter(function(server) {
            if (server && server.urls) {
              var urls = server.urls;
              if (typeof urls === 'string') {
                urls = [urls];
              }
              urls = urls.filter(function(url) {
                return (url.indexOf('turn:') === 0 &&
                    url.indexOf('transport=udp') !== -1 &&
                    url.indexOf('turn:[') === -1) ||
                    (url.indexOf('stun:') === 0 &&
                      browserDetails.version >= 14393);
              })[0];
              return !!urls;
            }
            return false;
          });
        }

        // per-track iceGathers, iceTransports, dtlsTransports, rtpSenders, ...
        // everything that is needed to describe a SDP m-line.
        this.transceivers = [];

        // since the iceGatherer is currently created in createOffer but we
        // must not emit candidates until after setLocalDescription we buffer
        // them in this array.
        this._localIceCandidatesBuffer = [];
      };

      window.RTCPeerConnection.prototype._emitBufferedCandidates = function() {
        var self = this;
        var sections = SDPUtils.splitSections(self.localDescription.sdp);
        // FIXME: need to apply ice candidates in a way which is async but
        // in-order
        this._localIceCandidatesBuffer.forEach(function(event) {
          var end = !event.candidate || Object.keys(event.candidate).length === 0;
          if (end) {
            for (var j = 1; j < sections.length; j++) {
              if (sections[j].indexOf('\r\na=end-of-candidates\r\n') === -1) {
                sections[j] += 'a=end-of-candidates\r\n';
              }
            }
          } else if (event.candidate.candidate.indexOf('typ endOfCandidates')
              === -1) {
            sections[event.candidate.sdpMLineIndex + 1] +=
                'a=' + event.candidate.candidate + '\r\n';
          }
          self.localDescription.sdp = sections.join('');
          self.dispatchEvent(event);
          if (self.onicecandidate !== null) {
            self.onicecandidate(event);
          }
          if (!event.candidate && self.iceGatheringState !== 'complete') {
            var complete = self.transceivers.every(function(transceiver) {
              return transceiver.iceGatherer &&
                  transceiver.iceGatherer.state === 'completed';
            });
            if (complete) {
              self.iceGatheringState = 'complete';
            }
          }
        });
        this._localIceCandidatesBuffer = [];
      };

      window.RTCPeerConnection.prototype.addStream = function(stream) {
        // Clone is necessary for local demos mostly, attaching directly
        // to two different senders does not work (build 10547).
        this.localStreams.push(stream.clone());
        this._maybeFireNegotiationNeeded();
      };

      window.RTCPeerConnection.prototype.removeStream = function(stream) {
        var idx = this.localStreams.indexOf(stream);
        if (idx > -1) {
          this.localStreams.splice(idx, 1);
          this._maybeFireNegotiationNeeded();
        }
      };

      window.RTCPeerConnection.prototype.getSenders = function() {
        return this.transceivers.filter(function(transceiver) {
          return !!transceiver.rtpSender;
        })
        .map(function(transceiver) {
          return transceiver.rtpSender;
        });
      };

      window.RTCPeerConnection.prototype.getReceivers = function() {
        return this.transceivers.filter(function(transceiver) {
          return !!transceiver.rtpReceiver;
        })
        .map(function(transceiver) {
          return transceiver.rtpReceiver;
        });
      };

      // Determines the intersection of local and remote capabilities.
      window.RTCPeerConnection.prototype._getCommonCapabilities =
          function(localCapabilities, remoteCapabilities) {
            var commonCapabilities = {
              codecs: [],
              headerExtensions: [],
              fecMechanisms: []
            };
            localCapabilities.codecs.forEach(function(lCodec) {
              for (var i = 0; i < remoteCapabilities.codecs.length; i++) {
                var rCodec = remoteCapabilities.codecs[i];
                if (lCodec.name.toLowerCase() === rCodec.name.toLowerCase() &&
                    lCodec.clockRate === rCodec.clockRate &&
                    lCodec.numChannels === rCodec.numChannels) {
                  // push rCodec so we reply with offerer payload type
                  commonCapabilities.codecs.push(rCodec);

                  // determine common feedback mechanisms
                  rCodec.rtcpFeedback = rCodec.rtcpFeedback.filter(function(fb) {
                    for (var j = 0; j < lCodec.rtcpFeedback.length; j++) {
                      if (lCodec.rtcpFeedback[j].type === fb.type &&
                          lCodec.rtcpFeedback[j].parameter === fb.parameter) {
                        return true;
                      }
                    }
                    return false;
                  });
                  // FIXME: also need to determine .parameters
                  //  see https://github.com/openpeer/ortc/issues/569
                  break;
                }
              }
            });

            localCapabilities.headerExtensions
                .forEach(function(lHeaderExtension) {
                  for (var i = 0; i < remoteCapabilities.headerExtensions.length;
                       i++) {
                    var rHeaderExtension = remoteCapabilities.headerExtensions[i];
                    if (lHeaderExtension.uri === rHeaderExtension.uri) {
                      commonCapabilities.headerExtensions.push(rHeaderExtension);
                      break;
                    }
                  }
                });

            // FIXME: fecMechanisms
            return commonCapabilities;
          };

      // Create ICE gatherer, ICE transport and DTLS transport.
      window.RTCPeerConnection.prototype._createIceAndDtlsTransports =
          function(mid, sdpMLineIndex) {
            var self = this;
            var iceGatherer = new RTCIceGatherer(self.iceOptions);
            var iceTransport = new RTCIceTransport(iceGatherer);
            iceGatherer.onlocalcandidate = function(evt) {
              var event = new Event('icecandidate');
              event.candidate = {sdpMid: mid, sdpMLineIndex: sdpMLineIndex};

              var cand = evt.candidate;
              var end = !cand || Object.keys(cand).length === 0;
              // Edge emits an empty object for RTCIceCandidateComplete‥
              if (end) {
                // polyfill since RTCIceGatherer.state is not implemented in
                // Edge 10547 yet.
                if (iceGatherer.state === undefined) {
                  iceGatherer.state = 'completed';
                }

                // Emit a candidate with type endOfCandidates to make the samples
                // work. Edge requires addIceCandidate with this empty candidate
                // to start checking. The real solution is to signal
                // end-of-candidates to the other side when getting the null
                // candidate but some apps (like the samples) don't do that.
                event.candidate.candidate =
                    'candidate:1 1 udp 1 0.0.0.0 9 typ endOfCandidates';
              } else {
                // RTCIceCandidate doesn't have a component, needs to be added
                cand.component = iceTransport.component === 'RTCP' ? 2 : 1;
                event.candidate.candidate = SDPUtils.writeCandidate(cand);
              }

              // update local description.
              var sections = SDPUtils.splitSections(self.localDescription.sdp);
              if (event.candidate.candidate.indexOf('typ endOfCandidates')
                  === -1) {
                sections[event.candidate.sdpMLineIndex + 1] +=
                    'a=' + event.candidate.candidate + '\r\n';
              } else {
                sections[event.candidate.sdpMLineIndex + 1] +=
                    'a=end-of-candidates\r\n';
              }
              self.localDescription.sdp = sections.join('');

              var complete = self.transceivers.every(function(transceiver) {
                return transceiver.iceGatherer &&
                    transceiver.iceGatherer.state === 'completed';
              });

              // Emit candidate if localDescription is set.
              // Also emits null candidate when all gatherers are complete.
              switch (self.iceGatheringState) {
                case 'new':
                  self._localIceCandidatesBuffer.push(event);
                  if (end && complete) {
                    self._localIceCandidatesBuffer.push(
                        new Event('icecandidate'));
                  }
                  break;
                case 'gathering':
                  self._emitBufferedCandidates();
                  self.dispatchEvent(event);
                  if (self.onicecandidate !== null) {
                    self.onicecandidate(event);
                  }
                  if (complete) {
                    self.dispatchEvent(new Event('icecandidate'));
                    if (self.onicecandidate !== null) {
                      self.onicecandidate(new Event('icecandidate'));
                    }
                    self.iceGatheringState = 'complete';
                  }
                  break;
                case 'complete':
                  // should not happen... currently!
                  break;
                default: // no-op.
                  break;
              }
            };
            iceTransport.onicestatechange = function() {
              self._updateConnectionState();
            };

            var dtlsTransport = new RTCDtlsTransport(iceTransport);
            dtlsTransport.ondtlsstatechange = function() {
              self._updateConnectionState();
            };
            dtlsTransport.onerror = function() {
              // onerror does not set state to failed by itself.
              dtlsTransport.state = 'failed';
              self._updateConnectionState();
            };

            return {
              iceGatherer: iceGatherer,
              iceTransport: iceTransport,
              dtlsTransport: dtlsTransport
            };
          };

      // Start the RTP Sender and Receiver for a transceiver.
      window.RTCPeerConnection.prototype._transceive = function(transceiver,
          send, recv) {
        var params = this._getCommonCapabilities(transceiver.localCapabilities,
            transceiver.remoteCapabilities);
        if (send && transceiver.rtpSender) {
          params.encodings = transceiver.sendEncodingParameters;
          params.rtcp = {
            cname: SDPUtils.localCName
          };
          if (transceiver.recvEncodingParameters.length) {
            params.rtcp.ssrc = transceiver.recvEncodingParameters[0].ssrc;
          }
          transceiver.rtpSender.send(params);
        }
        if (recv && transceiver.rtpReceiver) {
          params.encodings = transceiver.recvEncodingParameters;
          params.rtcp = {
            cname: transceiver.cname
          };
          if (transceiver.sendEncodingParameters.length) {
            params.rtcp.ssrc = transceiver.sendEncodingParameters[0].ssrc;
          }
          transceiver.rtpReceiver.receive(params);
        }
      };

      window.RTCPeerConnection.prototype.setLocalDescription =
          function(description) {
            var self = this;
            var sections;
            var sessionpart;
            if (description.type === 'offer') {
              // FIXME: What was the purpose of this empty if statement?
              // if (!this._pendingOffer) {
              // } else {
              if (this._pendingOffer) {
                // VERY limited support for SDP munging. Limited to:
                // * changing the order of codecs
                sections = SDPUtils.splitSections(description.sdp);
                sessionpart = sections.shift();
                sections.forEach(function(mediaSection, sdpMLineIndex) {
                  var caps = SDPUtils.parseRtpParameters(mediaSection);
                  self._pendingOffer[sdpMLineIndex].localCapabilities = caps;
                });
                this.transceivers = this._pendingOffer;
                delete this._pendingOffer;
              }
            } else if (description.type === 'answer') {
              sections = SDPUtils.splitSections(self.remoteDescription.sdp);
              sessionpart = sections.shift();
              var isIceLite = SDPUtils.matchPrefix(sessionpart,
                  'a=ice-lite').length > 0;
              sections.forEach(function(mediaSection, sdpMLineIndex) {
                var transceiver = self.transceivers[sdpMLineIndex];
                var iceGatherer = transceiver.iceGatherer;
                var iceTransport = transceiver.iceTransport;
                var dtlsTransport = transceiver.dtlsTransport;
                var localCapabilities = transceiver.localCapabilities;
                var remoteCapabilities = transceiver.remoteCapabilities;

                var rejected = mediaSection.split('\n', 1)[0]
                    .split(' ', 2)[1] === '0';

                if (!rejected && !transceiver.isDatachannel) {
                  var remoteIceParameters = SDPUtils.getIceParameters(
                      mediaSection, sessionpart);
                  if (isIceLite) {
                    var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
                    .map(function(cand) {
                      return SDPUtils.parseCandidate(cand);
                    })
                    .filter(function(cand) {
                      return cand.component === '1';
                    });
                    // ice-lite only includes host candidates in the SDP so we can
                    // use setRemoteCandidates (which implies an
                    // RTCIceCandidateComplete)
                    if (cands.length) {
                      iceTransport.setRemoteCandidates(cands);
                    }
                  }
                  var remoteDtlsParameters = SDPUtils.getDtlsParameters(
                      mediaSection, sessionpart);
                  if (isIceLite) {
                    remoteDtlsParameters.role = 'server';
                  }

                  if (!self.usingBundle || sdpMLineIndex === 0) {
                    iceTransport.start(iceGatherer, remoteIceParameters,
                        isIceLite ? 'controlling' : 'controlled');
                    dtlsTransport.start(remoteDtlsParameters);
                  }

                  // Calculate intersection of capabilities.
                  var params = self._getCommonCapabilities(localCapabilities,
                      remoteCapabilities);

                  // Start the RTCRtpSender. The RTCRtpReceiver for this
                  // transceiver has already been started in setRemoteDescription.
                  self._transceive(transceiver,
                      params.codecs.length > 0,
                      false);
                }
              });
            }

            this.localDescription = {
              type: description.type,
              sdp: description.sdp
            };
            switch (description.type) {
              case 'offer':
                this._updateSignalingState('have-local-offer');
                break;
              case 'answer':
                this._updateSignalingState('stable');
                break;
              default:
                throw new TypeError('unsupported type "' + description.type +
                    '"');
            }

            // If a success callback was provided, emit ICE candidates after it
            // has been executed. Otherwise, emit callback after the Promise is
            // resolved.
            var hasCallback = arguments.length > 1 &&
              typeof arguments[1] === 'function';
            if (hasCallback) {
              var cb = arguments[1];
              window.setTimeout(function() {
                cb();
                if (self.iceGatheringState === 'new') {
                  self.iceGatheringState = 'gathering';
                }
                self._emitBufferedCandidates();
              }, 0);
            }
            var p = Promise.resolve();
            p.then(function() {
              if (!hasCallback) {
                if (self.iceGatheringState === 'new') {
                  self.iceGatheringState = 'gathering';
                }
                // Usually candidates will be emitted earlier.
                window.setTimeout(self._emitBufferedCandidates.bind(self), 500);
              }
            });
            return p;
          };

      window.RTCPeerConnection.prototype.setRemoteDescription =
          function(description) {
            var self = this;
            var stream = new MediaStream();
            var receiverList = [];
            var sections = SDPUtils.splitSections(description.sdp);
            var sessionpart = sections.shift();
            var isIceLite = SDPUtils.matchPrefix(sessionpart,
                'a=ice-lite').length > 0;
            this.usingBundle = SDPUtils.matchPrefix(sessionpart,
                'a=group:BUNDLE ').length > 0;
            sections.forEach(function(mediaSection, sdpMLineIndex) {
              var lines = SDPUtils.splitLines(mediaSection);
              var mline = lines[0].substr(2).split(' ');
              var kind = mline[0];
              var rejected = mline[1] === '0';
              var direction = SDPUtils.getDirection(mediaSection, sessionpart);

              var mid = SDPUtils.matchPrefix(mediaSection, 'a=mid:');
              if (mid.length) {
                mid = mid[0].substr(6);
              } else {
                mid = SDPUtils.generateIdentifier();
              }

              // Reject datachannels which are not implemented yet.
              if (kind === 'application' && mline[2] === 'DTLS/SCTP') {
                self.transceivers[sdpMLineIndex] = {
                  mid: mid,
                  isDatachannel: true
                };
                return;
              }

              var transceiver;
              var iceGatherer;
              var iceTransport;
              var dtlsTransport;
              var rtpSender;
              var rtpReceiver;
              var sendEncodingParameters;
              var recvEncodingParameters;
              var localCapabilities;

              var track;
              // FIXME: ensure the mediaSection has rtcp-mux set.
              var remoteCapabilities = SDPUtils.parseRtpParameters(mediaSection);
              var remoteIceParameters;
              var remoteDtlsParameters;
              if (!rejected) {
                remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
                    sessionpart);
                remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
                    sessionpart);
                remoteDtlsParameters.role = 'client';
              }
              recvEncodingParameters =
                  SDPUtils.parseRtpEncodingParameters(mediaSection);

              var cname;
              // Gets the first SSRC. Note that with RTX there might be multiple
              // SSRCs.
              var remoteSsrc = SDPUtils.matchPrefix(mediaSection, 'a=ssrc:')
                  .map(function(line) {
                    return SDPUtils.parseSsrcMedia(line);
                  })
                  .filter(function(obj) {
                    return obj.attribute === 'cname';
                  })[0];
              if (remoteSsrc) {
                cname = remoteSsrc.value;
              }

              var isComplete = SDPUtils.matchPrefix(mediaSection,
                  'a=end-of-candidates', sessionpart).length > 0;
              var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
                  .map(function(cand) {
                    return SDPUtils.parseCandidate(cand);
                  })
                  .filter(function(cand) {
                    return cand.component === '1';
                  });
              if (description.type === 'offer' && !rejected) {
                var transports = self.usingBundle && sdpMLineIndex > 0 ? {
                  iceGatherer: self.transceivers[0].iceGatherer,
                  iceTransport: self.transceivers[0].iceTransport,
                  dtlsTransport: self.transceivers[0].dtlsTransport
                } : self._createIceAndDtlsTransports(mid, sdpMLineIndex);

                if (isComplete) {
                  transports.iceTransport.setRemoteCandidates(cands);
                }

                localCapabilities = RTCRtpReceiver.getCapabilities(kind);
                sendEncodingParameters = [{
                  ssrc: (2 * sdpMLineIndex + 2) * 1001
                }];

                rtpReceiver = new RTCRtpReceiver(transports.dtlsTransport, kind);

                track = rtpReceiver.track;
                receiverList.push([track, rtpReceiver]);
                // FIXME: not correct when there are multiple streams but that is
                // not currently supported in this shim.
                stream.addTrack(track);

                // FIXME: look at direction.
                if (self.localStreams.length > 0 &&
                    self.localStreams[0].getTracks().length >= sdpMLineIndex) {
                  var localTrack;
                  if (kind === 'audio') {
                    localTrack = self.localStreams[0].getAudioTracks()[0];
                  } else if (kind === 'video') {
                    localTrack = self.localStreams[0].getVideoTracks()[0];
                  }
                  if (localTrack) {
                    rtpSender = new RTCRtpSender(localTrack,
                        transports.dtlsTransport);
                  }
                }

                self.transceivers[sdpMLineIndex] = {
                  iceGatherer: transports.iceGatherer,
                  iceTransport: transports.iceTransport,
                  dtlsTransport: transports.dtlsTransport,
                  localCapabilities: localCapabilities,
                  remoteCapabilities: remoteCapabilities,
                  rtpSender: rtpSender,
                  rtpReceiver: rtpReceiver,
                  kind: kind,
                  mid: mid,
                  cname: cname,
                  sendEncodingParameters: sendEncodingParameters,
                  recvEncodingParameters: recvEncodingParameters
                };
                // Start the RTCRtpReceiver now. The RTPSender is started in
                // setLocalDescription.
                self._transceive(self.transceivers[sdpMLineIndex],
                    false,
                    direction === 'sendrecv' || direction === 'sendonly');
              } else if (description.type === 'answer' && !rejected) {
                transceiver = self.transceivers[sdpMLineIndex];
                iceGatherer = transceiver.iceGatherer;
                iceTransport = transceiver.iceTransport;
                dtlsTransport = transceiver.dtlsTransport;
                rtpSender = transceiver.rtpSender;
                rtpReceiver = transceiver.rtpReceiver;
                sendEncodingParameters = transceiver.sendEncodingParameters;
                localCapabilities = transceiver.localCapabilities;

                self.transceivers[sdpMLineIndex].recvEncodingParameters =
                    recvEncodingParameters;
                self.transceivers[sdpMLineIndex].remoteCapabilities =
                    remoteCapabilities;
                self.transceivers[sdpMLineIndex].cname = cname;

                if ((isIceLite || isComplete) && cands.length) {
                  iceTransport.setRemoteCandidates(cands);
                }
                if (!self.usingBundle || sdpMLineIndex === 0) {
                  iceTransport.start(iceGatherer, remoteIceParameters,
                      'controlling');
                  dtlsTransport.start(remoteDtlsParameters);
                }

                self._transceive(transceiver,
                    direction === 'sendrecv' || direction === 'recvonly',
                    direction === 'sendrecv' || direction === 'sendonly');

                if (rtpReceiver &&
                    (direction === 'sendrecv' || direction === 'sendonly')) {
                  track = rtpReceiver.track;
                  receiverList.push([track, rtpReceiver]);
                  stream.addTrack(track);
                } else {
                  // FIXME: actually the receiver should be created later.
                  delete transceiver.rtpReceiver;
                }
              }
            });

            this.remoteDescription = {
              type: description.type,
              sdp: description.sdp
            };
            switch (description.type) {
              case 'offer':
                this._updateSignalingState('have-remote-offer');
                break;
              case 'answer':
                this._updateSignalingState('stable');
                break;
              default:
                throw new TypeError('unsupported type "' + description.type +
                    '"');
            }
            if (stream.getTracks().length) {
              self.remoteStreams.push(stream);
              window.setTimeout(function() {
                var event = new Event('addstream');
                event.stream = stream;
                self.dispatchEvent(event);
                if (self.onaddstream !== null) {
                  window.setTimeout(function() {
                    self.onaddstream(event);
                  }, 0);
                }

                receiverList.forEach(function(item) {
                  var track = item[0];
                  var receiver = item[1];
                  var trackEvent = new Event('track');
                  trackEvent.track = track;
                  trackEvent.receiver = receiver;
                  trackEvent.streams = [stream];
                  self.dispatchEvent(event);
                  if (self.ontrack !== null) {
                    window.setTimeout(function() {
                      self.ontrack(trackEvent);
                    }, 0);
                  }
                });
              }, 0);
            }
            if (arguments.length > 1 && typeof arguments[1] === 'function') {
              window.setTimeout(arguments[1], 0);
            }
            return Promise.resolve();
          };

      window.RTCPeerConnection.prototype.close = function() {
        this.transceivers.forEach(function(transceiver) {
          /* not yet
          if (transceiver.iceGatherer) {
            transceiver.iceGatherer.close();
          }
          */
          if (transceiver.iceTransport) {
            transceiver.iceTransport.stop();
          }
          if (transceiver.dtlsTransport) {
            transceiver.dtlsTransport.stop();
          }
          if (transceiver.rtpSender) {
            transceiver.rtpSender.stop();
          }
          if (transceiver.rtpReceiver) {
            transceiver.rtpReceiver.stop();
          }
        });
        // FIXME: clean up tracks, local streams, remote streams, etc
        this._updateSignalingState('closed');
      };

      // Update the signaling state.
      window.RTCPeerConnection.prototype._updateSignalingState =
          function(newState) {
            this.signalingState = newState;
            var event = new Event('signalingstatechange');
            this.dispatchEvent(event);
            if (this.onsignalingstatechange !== null) {
              this.onsignalingstatechange(event);
            }
          };

      // Determine whether to fire the negotiationneeded event.
      window.RTCPeerConnection.prototype._maybeFireNegotiationNeeded =
          function() {
            // Fire away (for now).
            var event = new Event('negotiationneeded');
            this.dispatchEvent(event);
            if (this.onnegotiationneeded !== null) {
              this.onnegotiationneeded(event);
            }
          };

      // Update the connection state.
      window.RTCPeerConnection.prototype._updateConnectionState = function() {
        var self = this;
        var newState;
        var states = {
          'new': 0,
          closed: 0,
          connecting: 0,
          checking: 0,
          connected: 0,
          completed: 0,
          failed: 0
        };
        this.transceivers.forEach(function(transceiver) {
          states[transceiver.iceTransport.state]++;
          states[transceiver.dtlsTransport.state]++;
        });
        // ICETransport.completed and connected are the same for this purpose.
        states.connected += states.completed;

        newState = 'new';
        if (states.failed > 0) {
          newState = 'failed';
        } else if (states.connecting > 0 || states.checking > 0) {
          newState = 'connecting';
        } else if (states.disconnected > 0) {
          newState = 'disconnected';
        } else if (states.new > 0) {
          newState = 'new';
        } else if (states.connected > 0 || states.completed > 0) {
          newState = 'connected';
        }

        if (newState !== self.iceConnectionState) {
          self.iceConnectionState = newState;
          var event = new Event('iceconnectionstatechange');
          this.dispatchEvent(event);
          if (this.oniceconnectionstatechange !== null) {
            this.oniceconnectionstatechange(event);
          }
        }
      };

      window.RTCPeerConnection.prototype.createOffer = function() {
        var self = this;
        if (this._pendingOffer) {
          throw new Error('createOffer called while there is a pending offer.');
        }
        var offerOptions;
        if (arguments.length === 1 && typeof arguments[0] !== 'function') {
          offerOptions = arguments[0];
        } else if (arguments.length === 3) {
          offerOptions = arguments[2];
        }

        var tracks = [];
        var numAudioTracks = 0;
        var numVideoTracks = 0;
        // Default to sendrecv.
        if (this.localStreams.length) {
          numAudioTracks = this.localStreams[0].getAudioTracks().length;
          numVideoTracks = this.localStreams[0].getVideoTracks().length;
        }
        // Determine number of audio and video tracks we need to send/recv.
        if (offerOptions) {
          // Reject Chrome legacy constraints.
          if (offerOptions.mandatory || offerOptions.optional) {
            throw new TypeError(
                'Legacy mandatory/optional constraints not supported.');
          }
          if (offerOptions.offerToReceiveAudio !== undefined) {
            numAudioTracks = offerOptions.offerToReceiveAudio;
          }
          if (offerOptions.offerToReceiveVideo !== undefined) {
            numVideoTracks = offerOptions.offerToReceiveVideo;
          }
        }
        if (this.localStreams.length) {
          // Push local streams.
          this.localStreams[0].getTracks().forEach(function(track) {
            tracks.push({
              kind: track.kind,
              track: track,
              wantReceive: track.kind === 'audio' ?
                  numAudioTracks > 0 : numVideoTracks > 0
            });
            if (track.kind === 'audio') {
              numAudioTracks--;
            } else if (track.kind === 'video') {
              numVideoTracks--;
            }
          });
        }
        // Create M-lines for recvonly streams.
        while (numAudioTracks > 0 || numVideoTracks > 0) {
          if (numAudioTracks > 0) {
            tracks.push({
              kind: 'audio',
              wantReceive: true
            });
            numAudioTracks--;
          }
          if (numVideoTracks > 0) {
            tracks.push({
              kind: 'video',
              wantReceive: true
            });
            numVideoTracks--;
          }
        }

        var sdp = SDPUtils.writeSessionBoilerplate();
        var transceivers = [];
        tracks.forEach(function(mline, sdpMLineIndex) {
          // For each track, create an ice gatherer, ice transport,
          // dtls transport, potentially rtpsender and rtpreceiver.
          var track = mline.track;
          var kind = mline.kind;
          var mid = SDPUtils.generateIdentifier();

          var transports = self.usingBundle && sdpMLineIndex > 0 ? {
            iceGatherer: transceivers[0].iceGatherer,
            iceTransport: transceivers[0].iceTransport,
            dtlsTransport: transceivers[0].dtlsTransport
          } : self._createIceAndDtlsTransports(mid, sdpMLineIndex);

          var localCapabilities = RTCRtpSender.getCapabilities(kind);
          var rtpSender;
          var rtpReceiver;

          // generate an ssrc now, to be used later in rtpSender.send
          var sendEncodingParameters = [{
            ssrc: (2 * sdpMLineIndex + 1) * 1001
          }];
          if (track) {
            rtpSender = new RTCRtpSender(track, transports.dtlsTransport);
          }

          if (mline.wantReceive) {
            rtpReceiver = new RTCRtpReceiver(transports.dtlsTransport, kind);
          }

          transceivers[sdpMLineIndex] = {
            iceGatherer: transports.iceGatherer,
            iceTransport: transports.iceTransport,
            dtlsTransport: transports.dtlsTransport,
            localCapabilities: localCapabilities,
            remoteCapabilities: null,
            rtpSender: rtpSender,
            rtpReceiver: rtpReceiver,
            kind: kind,
            mid: mid,
            sendEncodingParameters: sendEncodingParameters,
            recvEncodingParameters: null
          };
        });
        if (this.usingBundle) {
          sdp += 'a=group:BUNDLE ' + transceivers.map(function(t) {
            return t.mid;
          }).join(' ') + '\r\n';
        }
        tracks.forEach(function(mline, sdpMLineIndex) {
          var transceiver = transceivers[sdpMLineIndex];
          sdp += SDPUtils.writeMediaSection(transceiver,
              transceiver.localCapabilities, 'offer', self.localStreams[0]);
        });

        this._pendingOffer = transceivers;
        var desc = new RTCSessionDescription({
          type: 'offer',
          sdp: sdp
        });
        if (arguments.length && typeof arguments[0] === 'function') {
          window.setTimeout(arguments[0], 0, desc);
        }
        return Promise.resolve(desc);
      };

      window.RTCPeerConnection.prototype.createAnswer = function() {
        var self = this;

        var sdp = SDPUtils.writeSessionBoilerplate();
        if (this.usingBundle) {
          sdp += 'a=group:BUNDLE ' + this.transceivers.map(function(t) {
            return t.mid;
          }).join(' ') + '\r\n';
        }
        this.transceivers.forEach(function(transceiver) {
          if (transceiver.isDatachannel) {
            sdp += 'm=application 0 DTLS/SCTP 5000\r\n' +
                'c=IN IP4 0.0.0.0\r\n' +
                'a=mid:' + transceiver.mid + '\r\n';
            return;
          }
          // Calculate intersection of capabilities.
          var commonCapabilities = self._getCommonCapabilities(
              transceiver.localCapabilities,
              transceiver.remoteCapabilities);

          sdp += SDPUtils.writeMediaSection(transceiver, commonCapabilities,
              'answer', self.localStreams[0]);
        });

        var desc = new RTCSessionDescription({
          type: 'answer',
          sdp: sdp
        });
        if (arguments.length && typeof arguments[0] === 'function') {
          window.setTimeout(arguments[0], 0, desc);
        }
        return Promise.resolve(desc);
      };

      window.RTCPeerConnection.prototype.addIceCandidate = function(candidate) {
        if (candidate === null) {
          this.transceivers.forEach(function(transceiver) {
            transceiver.iceTransport.addRemoteCandidate({});
          });
        } else {
          var mLineIndex = candidate.sdpMLineIndex;
          if (candidate.sdpMid) {
            for (var i = 0; i < this.transceivers.length; i++) {
              if (this.transceivers[i].mid === candidate.sdpMid) {
                mLineIndex = i;
                break;
              }
            }
          }
          var transceiver = this.transceivers[mLineIndex];
          if (transceiver) {
            var cand = Object.keys(candidate.candidate).length > 0 ?
                SDPUtils.parseCandidate(candidate.candidate) : {};
            // Ignore Chrome's invalid candidates since Edge does not like them.
            if (cand.protocol === 'tcp' && (cand.port === 0 || cand.port === 9)) {
              return;
            }
            // Ignore RTCP candidates, we assume RTCP-MUX.
            if (cand.component !== '1') {
              return;
            }
            // A dirty hack to make samples work.
            if (cand.type === 'endOfCandidates') {
              cand = {};
            }
            transceiver.iceTransport.addRemoteCandidate(cand);

            // update the remoteDescription.
            var sections = SDPUtils.splitSections(this.remoteDescription.sdp);
            sections[mLineIndex + 1] += (cand.type ? candidate.candidate.trim()
                : 'a=end-of-candidates') + '\r\n';
            this.remoteDescription.sdp = sections.join('');
          }
        }
        if (arguments.length > 1 && typeof arguments[1] === 'function') {
          window.setTimeout(arguments[1], 0);
        }
        return Promise.resolve();
      };

      window.RTCPeerConnection.prototype.getStats = function() {
        var promises = [];
        this.transceivers.forEach(function(transceiver) {
          ['rtpSender', 'rtpReceiver', 'iceGatherer', 'iceTransport',
              'dtlsTransport'].forEach(function(method) {
                if (transceiver[method]) {
                  promises.push(transceiver[method].getStats());
                }
              });
        });
        var cb = arguments.length > 1 && typeof arguments[1] === 'function' &&
            arguments[1];
        return new Promise(function(resolve) {
          // shim getStats with maplike support
          var results = new Map();
          Promise.all(promises).then(function(res) {
            res.forEach(function(result) {
              Object.keys(result).forEach(function(id) {
                results.set(id, result[id]);
                results[id] = result[id];
              });
            });
            if (cb) {
              window.setTimeout(cb, 0, results);
            }
            resolve(results);
          });
        });
      };
    }
  };

  // Expose public methods.
  module.exports = {
    shimPeerConnection: edgeShim.shimPeerConnection,
    shimGetUserMedia: require('./getusermedia')
  };

  },{"../utils":10,"./getusermedia":6,"sdp":1}],6:[function(require,module,exports){
  /*
   *  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';

  // Expose public methods.
  module.exports = function() {
    var shimError_ = function(e) {
      return {
        name: {PermissionDeniedError: 'NotAllowedError'}[e.name] || e.name,
        message: e.message,
        constraint: e.constraint,
        toString: function() {
          return this.name;
        }
      };
    };

    // getUserMedia error shim.
    var origGetUserMedia = navigator.mediaDevices.getUserMedia.
        bind(navigator.mediaDevices);
    navigator.mediaDevices.getUserMedia = function(c) {
      return origGetUserMedia(c).catch(function(e) {
        return Promise.reject(shimError_(e));
      });
    };
  };

  },{}],7:[function(require,module,exports){
  /*
   *  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 browserDetails = require('../utils').browserDetails;

  var firefoxShim = {
    shimOnTrack: function() {
      if (typeof window === 'object' && window.RTCPeerConnection && !('ontrack' in
          window.RTCPeerConnection.prototype)) {
        Object.defineProperty(window.RTCPeerConnection.prototype, 'ontrack', {
          get: function() {
            return this._ontrack;
          },
          set: function(f) {
            if (this._ontrack) {
              this.removeEventListener('track', this._ontrack);
              this.removeEventListener('addstream', this._ontrackpoly);
            }
            this.addEventListener('track', this._ontrack = f);
            this.addEventListener('addstream', this._ontrackpoly = function(e) {
              e.stream.getTracks().forEach(function(track) {
                var event = new Event('track');
                event.track = track;
                event.receiver = {track: track};
                event.streams = [e.stream];
                this.dispatchEvent(event);
              }.bind(this));
            }.bind(this));
          }
        });
      }
    },

    shimSourceObject: function() {
      // Firefox has supported mozSrcObject since FF22, unprefixed in 42.
      if (typeof window === 'object') {
        if (window.HTMLMediaElement &&
          !('srcObject' in window.HTMLMediaElement.prototype)) {
          // Shim the srcObject property, once, when HTMLMediaElement is found.
          Object.defineProperty(window.HTMLMediaElement.prototype, 'srcObject', {
            get: function() {
              return this.mozSrcObject;
            },
            set: function(stream) {
              this.mozSrcObject = stream;
            }
          });
        }
      }
    },

    shimPeerConnection: function() {
      if (typeof window !== 'object' || !(window.RTCPeerConnection ||
          window.mozRTCPeerConnection)) {
        return; // probably media.peerconnection.enabled=false in about:config
      }
      // The RTCPeerConnection object.
      if (!window.RTCPeerConnection) {
        window.RTCPeerConnection = function(pcConfig, pcConstraints) {
          if (browserDetails.version < 38) {
            // .urls is not supported in FF < 38.
            // create RTCIceServers with a single url.
            if (pcConfig && pcConfig.iceServers) {
              var newIceServers = [];
              for (var i = 0; i < pcConfig.iceServers.length; i++) {
                var server = pcConfig.iceServers[i];
                if (server.hasOwnProperty('urls')) {
                  for (var j = 0; j < server.urls.length; j++) {
                    var newServer = {
                      url: server.urls[j]
                    };
                    if (server.urls[j].indexOf('turn') === 0) {
                      newServer.username = server.username;
                      newServer.credential = server.credential;
                    }
                    newIceServers.push(newServer);
                  }
                } else {
                  newIceServers.push(pcConfig.iceServers[i]);
                }
              }
              pcConfig.iceServers = newIceServers;
            }
          }
          return new mozRTCPeerConnection(pcConfig, pcConstraints);
        };
        window.RTCPeerConnection.prototype = mozRTCPeerConnection.prototype;

        // wrap static methods. Currently just generateCertificate.
        if (mozRTCPeerConnection.generateCertificate) {
          Object.defineProperty(window.RTCPeerConnection, 'generateCertificate', {
            get: function() {
              return mozRTCPeerConnection.generateCertificate;
            }
          });
        }

        window.RTCSessionDescription = mozRTCSessionDescription;
        window.RTCIceCandidate = mozRTCIceCandidate;
      }

      // shim away need for obsolete RTCIceCandidate/RTCSessionDescription.
      ['setLocalDescription', 'setRemoteDescription', 'addIceCandidate']
          .forEach(function(method) {
            var nativeMethod = RTCPeerConnection.prototype[method];
            RTCPeerConnection.prototype[method] = function() {
              arguments[0] = new ((method === 'addIceCandidate') ?
                  RTCIceCandidate : RTCSessionDescription)(arguments[0]);
              return nativeMethod.apply(this, arguments);
            };
          });

      // support for addIceCandidate(null)
      var nativeAddIceCandidate =
          RTCPeerConnection.prototype.addIceCandidate;
      RTCPeerConnection.prototype.addIceCandidate = function() {
        return arguments[0] === null ? Promise.resolve()
            : nativeAddIceCandidate.apply(this, arguments);
      };

      // shim getStats with maplike support
      var makeMapStats = function(stats) {
        var map = new Map();
        Object.keys(stats).forEach(function(key) {
          map.set(key, stats[key]);
          map[key] = stats[key];
        });
        return map;
      };

      var nativeGetStats = RTCPeerConnection.prototype.getStats;
      RTCPeerConnection.prototype.getStats = function(selector, onSucc, onErr) {
        return nativeGetStats.apply(this, [selector || null])
          .then(function(stats) {
            return makeMapStats(stats);
          })
          .then(onSucc, onErr);
      };
    }
  };

  // Expose public methods.
  module.exports = {
    shimOnTrack: firefoxShim.shimOnTrack,
    shimSourceObject: firefoxShim.shimSourceObject,
    shimPeerConnection: firefoxShim.shimPeerConnection,
    shimGetUserMedia: require('./getusermedia')
  };

  },{"../utils":10,"./getusermedia":8}],8:[function(require,module,exports){
  /*
   *  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 logging = require('../utils').log;
  var browserDetails = require('../utils').browserDetails;

  // Expose public methods.
  module.exports = function() {
    var shimError_ = function(e) {
      return {
        name: {
          SecurityError: 'NotAllowedError',
          PermissionDeniedError: 'NotAllowedError'
        }[e.name] || e.name,
        message: {
          'The operation is insecure.': 'The request is not allowed by the ' +
          'user agent or the platform in the current context.'
        }[e.message] || e.message,
        constraint: e.constraint,
        toString: function() {
          return this.name + (this.message && ': ') + this.message;
        }
      };
    };

    // getUserMedia constraints shim.
    var getUserMedia_ = function(constraints, onSuccess, onError) {
      var constraintsToFF37_ = function(c) {
        if (typeof c !== 'object' || c.require) {
          return c;
        }
        var require = [];
        Object.keys(c).forEach(function(key) {
          if (key === 'require' || key === 'advanced' || key === 'mediaSource') {
            return;
          }
          var r = c[key] = (typeof c[key] === 'object') ?
              c[key] : {ideal: c[key]};
          if (r.min !== undefined ||
              r.max !== undefined || r.exact !== undefined) {
            require.push(key);
          }
          if (r.exact !== undefined) {
            if (typeof r.exact === 'number') {
              r. min = r.max = r.exact;
            } else {
              c[key] = r.exact;
            }
            delete r.exact;
          }
          if (r.ideal !== undefined) {
            c.advanced = c.advanced || [];
            var oc = {};
            if (typeof r.ideal === 'number') {
              oc[key] = {min: r.ideal, max: r.ideal};
            } else {
              oc[key] = r.ideal;
            }
            c.advanced.push(oc);
            delete r.ideal;
            if (!Object.keys(r).length) {
              delete c[key];
            }
          }
        });
        if (require.length) {
          c.require = require;
        }
        return c;
      };
      constraints = JSON.parse(JSON.stringify(constraints));
      if (browserDetails.version < 38) {
        logging('spec: ' + JSON.stringify(constraints));
        if (constraints.audio) {
          constraints.audio = constraintsToFF37_(constraints.audio);
        }
        if (constraints.video) {
          constraints.video = constraintsToFF37_(constraints.video);
        }
        logging('ff37: ' + JSON.stringify(constraints));
      }
      return navigator.mozGetUserMedia(constraints, onSuccess, function(e) {
        onError(shimError_(e));
      });
    };

    // Returns the result of getUserMedia as a Promise.
    var getUserMediaPromise_ = function(constraints) {
      return new Promise(function(resolve, reject) {
        getUserMedia_(constraints, resolve, reject);
      });
    };

    // Shim for mediaDevices on older versions.
    if (!navigator.mediaDevices) {
      navigator.mediaDevices = {getUserMedia: getUserMediaPromise_,
        addEventListener: function() { },
        removeEventListener: function() { }
      };
    }
    navigator.mediaDevices.enumerateDevices =
        navigator.mediaDevices.enumerateDevices || function() {
          return new Promise(function(resolve) {
            var infos = [
              {kind: 'audioinput', deviceId: 'default', label: '', groupId: ''},
              {kind: 'videoinput', deviceId: 'default', label: '', groupId: ''}
            ];
            resolve(infos);
          });
        };

    if (browserDetails.version < 41) {
      // Work around http://bugzil.la/1169665
      var orgEnumerateDevices =
          navigator.mediaDevices.enumerateDevices.bind(navigator.mediaDevices);
      navigator.mediaDevices.enumerateDevices = function() {
        return orgEnumerateDevices().then(undefined, function(e) {
          if (e.name === 'NotFoundError') {
            return [];
          }
          throw e;
        });
      };
    }
    if (browserDetails.version < 49) {
      var origGetUserMedia = navigator.mediaDevices.getUserMedia.
          bind(navigator.mediaDevices);
      navigator.mediaDevices.getUserMedia = function(c) {
        return origGetUserMedia(c).catch(function(e) {
          return Promise.reject(shimError_(e));
        });
      };
    }
    navigator.getUserMedia = function(constraints, onSuccess, onError) {
      if (browserDetails.version < 44) {
        return getUserMedia_(constraints, onSuccess, onError);
      }
      // Replace Firefox 44+'s deprecation warning with unprefixed version.
      console.warn('navigator.getUserMedia has been replaced by ' +
                   'navigator.mediaDevices.getUserMedia');
      navigator.mediaDevices.getUserMedia(constraints).then(onSuccess, onError);
    };
  };

  },{"../utils":10}],9:[function(require,module,exports){
  /*
   *  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';
  var safariShim = {
    // TODO: DrAlex, should be here, double check against LayoutTests
    // shimOnTrack: function() { },

    // TODO: once the back-end for the mac port is done, add.
    // TODO: check for webkitGTK+
    // shimPeerConnection: function() { },

    shimGetUserMedia: function() {
      navigator.getUserMedia = navigator.webkitGetUserMedia;
    }
  };

  // Expose public methods.
  module.exports = {
    shimGetUserMedia: safariShim.shimGetUserMedia
    // TODO
    // shimOnTrack: safariShim.shimOnTrack,
    // shimPeerConnection: safariShim.shimPeerConnection
  };

  },{}],10:[function(require,module,exports){
  /*
   *  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 logDisabled_ = true;

  // Utility methods.
  var utils = {
    disableLog: function(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';
    },

    log: function() {
      if (typeof window === 'object') {
        if (logDisabled_) {
          return;
        }
        if (typeof console !== 'undefined' && typeof console.log === 'function') {
          console.log.apply(console, arguments);
        }
      }
    },

    /**
     * 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.
     */
    extractVersion: function(uastring, expr, pos) {
      var match = uastring.match(expr);
      return match && match.length >= pos && parseInt(match[pos], 10);
    },

    /**
     * Browser detector.
     *
     * @return {object} result containing browser and version
     *     properties.
     */
    detectBrowser: function() {
      // Returned result object.
      var result = {};
      result.browser = null;
      result.version = null;

      // Fail early if it's not a browser
      if (typeof window === 'undefined' || !window.navigator) {
        result.browser = 'Not a browser.';
        return result;
      }

      // Firefox.
      if (navigator.mozGetUserMedia) {
        result.browser = 'firefox';
        result.version = this.extractVersion(navigator.userAgent,
            /Firefox\/([0-9]+)\./, 1);

      // all webkit-based browsers
      } else if (navigator.webkitGetUserMedia) {
        // Chrome, Chromium, Webview, Opera, all use the chrome shim for now
        if (window.webkitRTCPeerConnection) {
          result.browser = 'chrome';
          result.version = this.extractVersion(navigator.userAgent,
            /Chrom(e|ium)\/([0-9]+)\./, 2);

        // Safari or unknown webkit-based
        // for the time being Safari has support for MediaStreams but not webRTC
        } else {
          // Safari UA substrings of interest for reference:
          // - webkit version:           AppleWebKit/602.1.25 (also used in Op,Cr)
          // - safari UI version:        Version/9.0.3 (unique to Safari)
          // - safari UI webkit version: Safari/601.4.4 (also used in Op,Cr)
          //
          // if the webkit version and safari UI webkit versions are equals,
          // ... this is a stable version.
          //
          // only the internal webkit version is important today to know if
          // media streams are supported
          //
          if (navigator.userAgent.match(/Version\/(\d+).(\d+)/)) {
            result.browser = 'safari';
            result.version = this.extractVersion(navigator.userAgent,
              /AppleWebKit\/([0-9]+)\./, 1);

          // unknown webkit-based browser
          } else {
            result.browser = 'Unsupported webkit-based browser ' +
                'with GUM support but no WebRTC support.';
            return result;
          }
        }

      // Edge.
      } else if (navigator.mediaDevices &&
          navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) {
        result.browser = 'edge';
        result.version = this.extractVersion(navigator.userAgent,
            /Edge\/(\d+).(\d+)$/, 2);

      // Default fallthrough: not supported.
      } else {
        result.browser = 'Not a supported browser.';
        return result;
      }

      return result;
    }
  };

  // Export.
  module.exports = {
    log: utils.log,
    disableLog: utils.disableLog,
    browserDetails: utils.detectBrowser(),
    extractVersion: utils.extractVersion
  };

  },{}]},{},[2])(2)
});
/* jshint ignore:end */

  // END OF INJECTION OF GOOGLE'S ADAPTER.JS CONTENT
  ///////////////////////////////////////////////////////////////////

  AdapterJS.parseWebrtcDetectedBrowser();

  ///////////////////////////////////////////////////////////////////
  // EXTENSION FOR CHROME, FIREFOX AND EDGE
  // Includes legacy functions
  // -- createIceServer
  // -- createIceServers
  // -- MediaStreamTrack.getSources
  //
  // and additional shims
  // -- attachMediaStream
  // -- reattachMediaStream
  // -- requestUserMedia
  // -- a call to AdapterJS.maybeThroughWebRTCReady (notifies WebRTC is ready)

  // Add support for legacy functions createIceServer and createIceServers
  if ( navigator.mozGetUserMedia ) {
    // Shim for MediaStreamTrack.getSources.
    MediaStreamTrack.getSources = function(successCb) {
      setTimeout(function() {
        var infos = [
          { kind: 'audio', id: 'default', label:'', facing:'' },
          { kind: 'video', id: 'default', label:'', facing:'' }
        ];
        successCb(infos);
      }, 0);
    };

    // Attach a media stream to an element.
    attachMediaStream = function(element, stream) {
      element.srcObject = stream;
      return element;
    };

    reattachMediaStream = function(to, from) {
      to.srcObject = from.srcObject;
      return to;
    };

    createIceServer = function (url, username, password) {
      console.warn('createIceServer is deprecated. It should be replaced with an application level implementation.');
      // Note: Google's import of AJS will auto-reverse to 'url': '...' for FF < 38

      var iceServer = null;
      var urlParts = url.split(':');
      if (urlParts[0].indexOf('stun') === 0) {
        iceServer = { urls : [url] };
      } else if (urlParts[0].indexOf('turn') === 0) {
        if (webrtcDetectedVersion < 27) {
          var turnUrlParts = url.split('?');
          if (turnUrlParts.length === 1 ||
            turnUrlParts[1].indexOf('transport=udp') === 0) {
            iceServer = {
              urls : [turnUrlParts[0]],
              credential : password,
              username : username
            };
          }
        } else {
          iceServer = {
            urls : [url],
            credential : password,
            username : username
          };
        }
      }
      return iceServer;
    };

    createIceServers = function (urls, username, password) {
      console.warn('createIceServers is deprecated. It should be replaced with an application level implementation.');

      var iceServers = [];
      for (i = 0; i < urls.length; i++) {
        var iceServer = createIceServer(urls[i], username, password);
        if (iceServer !== null) {
          iceServers.push(iceServer);
        }
      }
      return iceServers;
    };
  } else if ( navigator.webkitGetUserMedia ) {
    // Attach a media stream to an element.
    attachMediaStream = function(element, stream) {
      if (webrtcDetectedVersion >= 43) {
        element.srcObject = stream;
      } else if (typeof element.src !== 'undefined') {
        element.src = URL.createObjectURL(stream);
      } else {
        console.error('Error attaching stream to element.');
        // logging('Error attaching stream to element.');
      }
      return element;
    };

    reattachMediaStream = function(to, from) {
      if (webrtcDetectedVersion >= 43) {
        to.srcObject = from.srcObject;
      } else {
        to.src = from.src;
      }
      return to;
    };

    createIceServer = function (url, username, password) {
      console.warn('createIceServer is deprecated. It should be replaced with an application level implementation.');

      var iceServer = null;
      var urlParts = url.split(':');
      if (urlParts[0].indexOf('stun') === 0) {
        iceServer = { 'url' : url };
      } else if (urlParts[0].indexOf('turn') === 0) {
        iceServer = {
          'url' : url,
          'credential' : password,
          'username' : username
        };
      }
      return iceServer;
    };

    createIceServers = function (urls, username, password) {
      console.warn('createIceServers is deprecated. It should be replaced with an application level implementation.');

      var iceServers = [];
      if (webrtcDetectedVersion >= 34) {
        iceServers = {
          'urls' : urls,
          'credential' : password,
          'username' : username
        };
      } else {
        for (i = 0; i < urls.length; i++) {
          var iceServer = createIceServer(urls[i], username, password);
          if (iceServer !== null) {
            iceServers.push(iceServer);
          }
        }
      }
      return iceServers;
    };
  } else if (navigator.mediaDevices && navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) {
    // Attach a media stream to an element.
    attachMediaStream = function(element, stream) {
      element.srcObject = stream;
      return element;
    };

    reattachMediaStream = function(to, from) {
      to.srcObject = from.srcObject;
      return to;
    };
  }

  // Need to override attachMediaStream and reattachMediaStream
  // to support the plugin's logic
  attachMediaStream_base = attachMediaStream;

  if (webrtcDetectedBrowser === 'opera') {
    attachMediaStream_base = function (element, stream) {
      if (webrtcDetectedVersion > 38) {
        element.srcObject = stream;
      } else if (typeof element.src !== 'undefined') {
        element.src = URL.createObjectURL(stream);
      }
      // Else it doesn't work
    };
  }

  attachMediaStream = function (element, stream) {
    if ((webrtcDetectedBrowser === 'chrome' ||
         webrtcDetectedBrowser === 'opera') &&
        !stream) {
      // Chrome does not support "src = null"
      element.src = '';
    } else {
      attachMediaStream_base(element, stream);
    }
    return element;
  };
  reattachMediaStream_base = reattachMediaStream;
  reattachMediaStream = function (to, from) {
    reattachMediaStream_base(to, from);
    return to;
  };

  // Propagate attachMediaStream and gUM in window and AdapterJS
  window.attachMediaStream      = attachMediaStream;
  window.reattachMediaStream    = reattachMediaStream;
  window.getUserMedia           = function(constraints, onSuccess, onFailure) {
    navigator.getUserMedia(constraints, onSuccess, onFailure);
  };
  AdapterJS.attachMediaStream   = attachMediaStream;
  AdapterJS.reattachMediaStream = reattachMediaStream;
  AdapterJS.getUserMedia        = getUserMedia;

  // Removed Google defined promises when promise is not defined
  if (typeof Promise === 'undefined') {
    requestUserMedia = null;
  }

  AdapterJS.maybeThroughWebRTCReady();

  // END OF EXTENSION OF CHROME, FIREFOX AND EDGE
  ///////////////////////////////////////////////////////////////////

} else { // TRY TO USE PLUGIN

  ///////////////////////////////////////////////////////////////////
  // WEBRTC PLUGIN SHIM
  // Will automatically check if the plugin is available and inject it
  // into the DOM if it is.
  // When the plugin is not available, will prompt a banner to suggest installing it
  // Use AdapterJS.options.hidePluginInstallPrompt to prevent this banner from popping
  //
  // Shims the follwing:
  // -- getUserMedia
  // -- MediaStreamTrack
  // -- MediaStreamTrack.getSources
  // -- RTCPeerConnection
  // -- RTCSessionDescription
  // -- RTCIceCandidate
  // -- createIceServer
  // -- createIceServers
  // -- attachMediaStream
  // -- reattachMediaStream
  // -- webrtcDetectedBrowser
  // -- webrtcDetectedVersion

  // IE 9 is not offering an implementation of console.log until you open a console
  if (typeof console !== 'object' || typeof console.log !== 'function') {
    /* jshint -W020 */
    console = {} || console;
    // Implemented based on console specs from MDN
    // You may override these functions
    console.log = function (arg) {};
    console.info = function (arg) {};
    console.error = function (arg) {};
    console.dir = function (arg) {};
    console.exception = function (arg) {};
    console.trace = function (arg) {};
    console.warn = function (arg) {};
    console.count = function (arg) {};
    console.debug = function (arg) {};
    console.count = function (arg) {};
    console.time = function (arg) {};
    console.timeEnd = function (arg) {};
    console.group = function (arg) {};
    console.groupCollapsed = function (arg) {};
    console.groupEnd = function (arg) {};
    /* jshint +W020 */
  }
  AdapterJS.parseWebrtcDetectedBrowser();
  isIE = webrtcDetectedBrowser === 'IE';

  /* jshint -W035 */
  AdapterJS.WebRTCPlugin.WaitForPluginReady = function() {
    while (AdapterJS.WebRTCPlugin.pluginState !== AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
      /* empty because it needs to prevent the function from running. */
    }
  };
  /* jshint +W035 */

  AdapterJS.WebRTCPlugin.callWhenPluginReady = function (callback) {
    if (AdapterJS.WebRTCPlugin.pluginState === AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
      // Call immediately if possible
      // Once the plugin is set, the code will always take this path
      callback();
    } else {
      // otherwise start a 100ms interval
      var checkPluginReadyState = setInterval(function () {
        if (AdapterJS.WebRTCPlugin.pluginState === AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
          clearInterval(checkPluginReadyState);
          callback();
        }
      }, 100);
    }
  };

  AdapterJS.WebRTCPlugin.setLogLevel = function(logLevel) {
    AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
      AdapterJS.WebRTCPlugin.plugin.setLogLevel(logLevel);
    });
  };

  AdapterJS.WebRTCPlugin.injectPlugin = function () {
    // only inject once the page is ready
    if (document.readyState !== 'complete') {
      return;
    }

    // Prevent multiple injections
    if (AdapterJS.WebRTCPlugin.pluginState !== AdapterJS.WebRTCPlugin.PLUGIN_STATES.INITIALIZING) {
      return;
    }

    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.INJECTING;

    if (webrtcDetectedBrowser === 'IE' && webrtcDetectedVersion <= 10) {
      var frag = document.createDocumentFragment();
      AdapterJS.WebRTCPlugin.plugin = document.createElement('div');
      AdapterJS.WebRTCPlugin.plugin.innerHTML = '<object id="' +
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId + '" type="' +
        AdapterJS.WebRTCPlugin.pluginInfo.type + '" ' + 'width="1" height="1">' +
        '<param name="pluginId" value="' +
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId + '" /> ' +
        '<param name="windowless" value="false" /> ' +
        '<param name="pageId" value="' + AdapterJS.WebRTCPlugin.pageId + '" /> ' +
        '<param name="onload" value="' + AdapterJS.WebRTCPlugin.pluginInfo.onload + '" />' +
        '<param name="tag" value="' + AdapterJS.WebRTCPlugin.TAGS.NONE + '" />' +
        // uncomment to be able to use virtual cams
        (AdapterJS.options.getAllCams ? '<param name="forceGetAllCams" value="True" />':'') +

        '</object>';
      while (AdapterJS.WebRTCPlugin.plugin.firstChild) {
        frag.appendChild(AdapterJS.WebRTCPlugin.plugin.firstChild);
      }
      document.body.appendChild(frag);

      // Need to re-fetch the plugin
      AdapterJS.WebRTCPlugin.plugin =
        document.getElementById(AdapterJS.WebRTCPlugin.pluginInfo.pluginId);
    } else {
      // Load Plugin
      AdapterJS.WebRTCPlugin.plugin = document.createElement('object');
      AdapterJS.WebRTCPlugin.plugin.id =
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId;
      // IE will only start the plugin if it's ACTUALLY visible
      if (isIE) {
        AdapterJS.WebRTCPlugin.plugin.width = '1px';
        AdapterJS.WebRTCPlugin.plugin.height = '1px';
      } else { // The size of the plugin on Safari should be 0x0px
              // so that the autorisation prompt is at the top
        AdapterJS.WebRTCPlugin.plugin.width = '0px';
        AdapterJS.WebRTCPlugin.plugin.height = '0px';
      }
      AdapterJS.WebRTCPlugin.plugin.type = AdapterJS.WebRTCPlugin.pluginInfo.type;
      AdapterJS.WebRTCPlugin.plugin.innerHTML = '<param name="onload" value="' +
        AdapterJS.WebRTCPlugin.pluginInfo.onload + '">' +
        '<param name="pluginId" value="' +
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId + '">' +
        '<param name="windowless" value="false" /> ' +
        (AdapterJS.options.getAllCams ? '<param name="forceGetAllCams" value="True" />':'') +
        '<param name="pageId" value="' + AdapterJS.WebRTCPlugin.pageId + '">' +
        '<param name="tag" value="' + AdapterJS.WebRTCPlugin.TAGS.NONE + '" />';
      document.body.appendChild(AdapterJS.WebRTCPlugin.plugin);
    }


    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.INJECTED;
  };

  AdapterJS.WebRTCPlugin.isPluginInstalled =
    function (comName, plugName, plugType, installedCb, notInstalledCb) {
    if (!isIE) {
      var pluginArray = navigator.mimeTypes;
      for (var i = 0; i < pluginArray.length; i++) {
        if (pluginArray[i].type.indexOf(plugType) >= 0) {
          installedCb();
          return;
        }
      }
      notInstalledCb();
    } else {
      try {
        var axo = new ActiveXObject(comName + '.' + plugName);
      } catch (e) {
        notInstalledCb();
        return;
      }
      installedCb();
    }
  };

  AdapterJS.WebRTCPlugin.defineWebRTCInterface = function () {
    if (AdapterJS.WebRTCPlugin.pluginState ===
        AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
      console.error('AdapterJS - WebRTC interface has already been defined');
      return;
    }

    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.INITIALIZING;

    AdapterJS.isDefined = function (variable) {
      return variable !== null && variable !== undefined;
    };

    createIceServer = function (url, username, password) {
      var iceServer = null;
      var urlParts = url.split(':');
      if (urlParts[0].indexOf('stun') === 0) {
        iceServer = {
          'url' : url,
          'hasCredentials' : false
        };
      } else if (urlParts[0].indexOf('turn') === 0) {
        iceServer = {
          'url' : url,
          'hasCredentials' : true,
          'credential' : password,
          'username' : username
        };
      }
      return iceServer;
    };

    createIceServers = function (urls, username, password) {
      var iceServers = [];
      for (var i = 0; i < urls.length; ++i) {
        iceServers.push(createIceServer(urls[i], username, password));
      }
      return iceServers;
    };

    RTCSessionDescription = function (info) {
      AdapterJS.WebRTCPlugin.WaitForPluginReady();
      return AdapterJS.WebRTCPlugin.plugin.
        ConstructSessionDescription(info.type, info.sdp);
    };

    RTCPeerConnection = function (servers, constraints) {
      // Validate server argumenr
      if (!(servers === undefined ||
            servers === null ||
            Array.isArray(servers.iceServers))) {
        throw new Error('Failed to construct \'RTCPeerConnection\': Malformed RTCConfiguration');
      }

      // Validate constraints argument
      if (typeof constraints !== 'undefined' && constraints !== null) {
        var invalidConstraits = false;
        invalidConstraits |= typeof constraints !== 'object';
        invalidConstraits |= constraints.hasOwnProperty('mandatory') &&
                              constraints.mandatory !== undefined &&
                              constraints.mandatory !== null &&
                              constraints.mandatory.constructor !== Object;
        invalidConstraits |= constraints.hasOwnProperty('optional') &&
                              constraints.optional !== undefined &&
                              constraints.optional !== null &&
                              !Array.isArray(constraints.optional);
        if (invalidConstraits) {
          throw new Error('Failed to construct \'RTCPeerConnection\': Malformed constraints object');
        }
      }

      // Call relevant PeerConnection constructor according to plugin version
      AdapterJS.WebRTCPlugin.WaitForPluginReady();

      // RTCPeerConnection prototype from the old spec
      var iceServers = null;
      if (servers && Array.isArray(servers.iceServers)) {
        iceServers = servers.iceServers;
        for (var i = 0; i < iceServers.length; i++) {
          // Legacy plugin versions compatibility
          if (iceServers[i].urls && !iceServers[i].url) {
            iceServers[i].url = iceServers[i].urls;
          }
          iceServers[i].hasCredentials = AdapterJS.
            isDefined(iceServers[i].username) &&
            AdapterJS.isDefined(iceServers[i].credential);
        }
      }

      if (AdapterJS.WebRTCPlugin.plugin.PEER_CONNECTION_VERSION &&
          AdapterJS.WebRTCPlugin.plugin.PEER_CONNECTION_VERSION > 1) {
        // RTCPeerConnection prototype from the new spec
        if (iceServers) {
          servers.iceServers = iceServers;
        }
        return AdapterJS.WebRTCPlugin.plugin.PeerConnection(servers);
      } else {
        var mandatory = (constraints && constraints.mandatory) ?
          constraints.mandatory : null;
        var optional = (constraints && constraints.optional) ?
          constraints.optional : null;
        return AdapterJS.WebRTCPlugin.plugin.
          PeerConnection(AdapterJS.WebRTCPlugin.pageId,
          iceServers, mandatory, optional);
      }
    };

    MediaStreamTrack = function(){};
    MediaStreamTrack.getSources = function (callback) {
      AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
        AdapterJS.WebRTCPlugin.plugin.GetSources(callback);
      });
    };

    // getUserMedia constraints shim.
    // Copied from Chrome
    var constraintsToPlugin = function(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(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;
    };

    getUserMedia = function (constraints, successCallback, failureCallback) {
      var cc = {};
      cc.audio = constraints.audio ?
        constraintsToPlugin(constraints.audio) : false;
      cc.video = constraints.video ?
        constraintsToPlugin(constraints.video) : false;

      AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
        AdapterJS.WebRTCPlugin.plugin.
          getUserMedia(cc, successCallback, failureCallback);
      });
    };
    window.navigator.getUserMedia = getUserMedia;

    // Defined mediaDevices when promises are available
    if ( !navigator.mediaDevices &&
      typeof Promise !== 'undefined') {
      requestUserMedia = function(constraints) {
        return new Promise(function(resolve, reject) {
          getUserMedia(constraints, resolve, reject);
        });
      };
      navigator.mediaDevices = {getUserMedia: requestUserMedia,
                                enumerateDevices: function() {
        return new Promise(function(resolve) {
          var kinds = {audio: 'audioinput', video: 'videoinput'};
          return MediaStreamTrack.getSources(function(devices) {
            resolve(devices.map(function(device) {
              return {label: device.label,
                      kind: kinds[device.kind],
                      id: device.id,
                      deviceId: device.id,
                      groupId: ''};
            }));
          });
        });
      }};
    }

    attachMediaStream = function (element, stream) {
      if (!element || !element.parentNode) {
        return;
      }

      var streamId;
      if (stream === null) {
        streamId = '';
      } else {
        if (typeof stream.enableSoundTracks !== 'undefined') {
          stream.enableSoundTracks(true);
        }
        streamId = stream.id;
      }

      var elementId = element.id.length === 0 ? Math.random().toString(36).slice(2) : element.id;
      var nodeName = element.nodeName.toLowerCase();
      if (nodeName !== 'object') { // not a plugin <object> tag yet
        var tag;
        switch(nodeName) {
          case 'audio':
            tag = AdapterJS.WebRTCPlugin.TAGS.AUDIO;
            break;
          case 'video':
            tag = AdapterJS.WebRTCPlugin.TAGS.VIDEO;
            break;
          default:
            tag = AdapterJS.WebRTCPlugin.TAGS.NONE;
          }

        var frag = document.createDocumentFragment();
        var temp = document.createElement('div');
        var classHTML = '';
        if (element.className) {
          classHTML = 'class="' + element.className + '" ';
        } else if (element.attributes && element.attributes['class']) {
          classHTML = 'class="' + element.attributes['class'].value + '" ';
        }

        temp.innerHTML = '<object id="' + elementId + '" ' + classHTML +
          'type="' + AdapterJS.WebRTCPlugin.pluginInfo.type + '">' +
          '<param name="pluginId" value="' + elementId + '" /> ' +
          '<param name="pageId" value="' + AdapterJS.WebRTCPlugin.pageId + '" /> ' +
          '<param name="windowless" value="true" /> ' +
          '<param name="streamId" value="' + streamId + '" /> ' +
          '<param name="tag" value="' + tag + '" /> ' +
          '</object>';
        while (temp.firstChild) {
          frag.appendChild(temp.firstChild);
        }

        var height = '';
        var width = '';
        if (element.clientWidth || element.clientHeight) {
          width = element.clientWidth;
          height = element.clientHeight;
        }
        else if (element.width || element.height) {
          width = element.width;
          height = element.height;
        }

        element.parentNode.insertBefore(frag, element);
        frag = document.getElementById(elementId);
        frag.width = width;
        frag.height = height;
        element.parentNode.removeChild(element);
      } else { // already an <object> tag, just change the stream id
        var children = element.children;
        for (var i = 0; i !== children.length; ++i) {
          if (children[i].name === 'streamId') {
            children[i].value = streamId;
            break;
          }
        }
        element.setStreamId(streamId);
      }
      var newElement = document.getElementById(elementId);
      AdapterJS.forwardEventHandlers(newElement, element, Object.getPrototypeOf(element));

      return newElement;
    };

    reattachMediaStream = function (to, from) {
      var stream = null;
      var children = from.children;
      for (var i = 0; i !== children.length; ++i) {
        if (children[i].name === 'streamId') {
          AdapterJS.WebRTCPlugin.WaitForPluginReady();
          stream = AdapterJS.WebRTCPlugin.plugin
            .getStreamWithId(AdapterJS.WebRTCPlugin.pageId, children[i].value);
          break;
        }
      }
      if (stream !== null) {
        return attachMediaStream(to, stream);
      } else {
        console.log('Could not find the stream associated with this element');
      }
    };

    // Propagate attachMediaStream and gUM in window and AdapterJS
    window.attachMediaStream      = attachMediaStream;
    window.reattachMediaStream    = reattachMediaStream;
    window.getUserMedia           = getUserMedia;
    AdapterJS.attachMediaStream   = attachMediaStream;
    AdapterJS.reattachMediaStream = reattachMediaStream;
    AdapterJS.getUserMedia        = getUserMedia;

    AdapterJS.forwardEventHandlers = function (destElem, srcElem, prototype) {
      properties = Object.getOwnPropertyNames( prototype );
      for(var prop in properties) {
        if (prop) {
          propName = properties[prop];

          if (typeof propName.slice === 'function' &&
              propName.slice(0,2) === 'on' &&
              typeof srcElem[propName] === 'function') {
              AdapterJS.addEvent(destElem, propName.slice(2), srcElem[propName]);
          }
        }
      }
      var subPrototype = Object.getPrototypeOf(prototype);
      if(!!subPrototype) {
        AdapterJS.forwardEventHandlers(destElem, srcElem, subPrototype);
      }
    };

    RTCIceCandidate = function (candidate) {
      if (!candidate.sdpMid) {
        candidate.sdpMid = '';
      }

      AdapterJS.WebRTCPlugin.WaitForPluginReady();
      return AdapterJS.WebRTCPlugin.plugin.ConstructIceCandidate(
        candidate.sdpMid, candidate.sdpMLineIndex, candidate.candidate
      );
    };

    // inject plugin
    AdapterJS.addEvent(document, 'readystatechange', AdapterJS.WebRTCPlugin.injectPlugin);
    AdapterJS.WebRTCPlugin.injectPlugin();
  };

  // This function will be called if the plugin is needed (browser different
  // from Chrome or Firefox), but the plugin is not installed.
  AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCb = AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCb ||
    function() {
      AdapterJS.addEvent(document,
                        'readystatechange',
                         AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCbPriv);
      AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCbPriv();
    };

  AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCbPriv = function () {
    if (AdapterJS.options.hidePluginInstallPrompt) {
      return;
    }

    var downloadLink = AdapterJS.WebRTCPlugin.pluginInfo.downloadLink;
    if(downloadLink) { // if download link
      var popupString;
      if (AdapterJS.WebRTCPlugin.pluginInfo.portalLink) { // is portal link
       popupString = 'This website requires you to install the ' +
        ' <a href="' + AdapterJS.WebRTCPlugin.pluginInfo.portalLink +
        '" target="_blank">' + AdapterJS.WebRTCPlugin.pluginInfo.companyName +
        ' WebRTC Plugin</a>' +
        ' to work on this browser.';
      } else { // no portal link, just print a generic explanation
       popupString = AdapterJS.TEXT.PLUGIN.REQUIRE_INSTALLATION;
      }

      AdapterJS.renderNotificationBar(popupString, AdapterJS.TEXT.PLUGIN.BUTTON, downloadLink);
    } else { // no download link, just print a generic explanation
      AdapterJS.renderNotificationBar(AdapterJS.TEXT.PLUGIN.NOT_SUPPORTED);
    }
  };


  // Try to detect the plugin and act accordingly
  AdapterJS.WebRTCPlugin.isPluginInstalled(
    AdapterJS.WebRTCPlugin.pluginInfo.prefix,
    AdapterJS.WebRTCPlugin.pluginInfo.plugName,
    AdapterJS.WebRTCPlugin.pluginInfo.type,
    AdapterJS.WebRTCPlugin.defineWebRTCInterface,
    AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCb);

  // END OF WEBRTC PLUGIN SHIM
  ///////////////////////////////////////////////////////////////////
}

(function () {

  'use strict';

  var baseGetUserMedia = null;

  AdapterJS.TEXT.EXTENSION = {
    REQUIRE_INSTALLATION_FF: 'To enable screensharing you need to install the Skylink WebRTC tools Firefox Add-on.',
    REQUIRE_INSTALLATION_CHROME: 'To enable screensharing you need to install the Skylink WebRTC tools Chrome Extension.',
    REQUIRE_REFRESH: 'Please refresh this page after the Skylink WebRTC tools extension has been installed.',
    BUTTON_FF: 'Install Now',
    BUTTON_CHROME: 'Go to Chrome Web Store'
  };

  var clone = function(obj) {
    if (null === obj || 'object' !== typeof obj) {
      return obj;
    }
    var copy = obj.constructor();
    for (var attr in obj) {
      if (obj.hasOwnProperty(attr)) {
        copy[attr] = obj[attr];
      }
    }
    return copy;
  };

  if (window.navigator.mozGetUserMedia) {
    baseGetUserMedia = window.navigator.getUserMedia;

    navigator.getUserMedia = function (constraints, successCb, failureCb) {

      if (constraints && constraints.video && !!constraints.video.mediaSource) {
        // intercepting screensharing requests

        // Invalid mediaSource for firefox, only "screen" and "window" are supported
        if (constraints.video.mediaSource !== 'screen' && constraints.video.mediaSource !== 'window') {
          failureCb(new Error('GetUserMedia: Only "screen" and "window" are supported as mediaSource constraints'));
          return;
        }

        var updatedConstraints = clone(constraints);

        //constraints.video.mediaSource = constraints.video.mediaSource;
        updatedConstraints.video.mozMediaSource = updatedConstraints.video.mediaSource;

        // so generally, it requires for document.readyState to be completed before the getUserMedia could be invoked.
        // strange but this works anyway
        var checkIfReady = setInterval(function () {
          if (document.readyState === 'complete') {
            clearInterval(checkIfReady);

            baseGetUserMedia(updatedConstraints, successCb, function (error) {
              if (['PermissionDeniedError', 'SecurityError'].indexOf(error.name) > -1 && window.parent.location.protocol === 'https:') {
                AdapterJS.renderNotificationBar(AdapterJS.TEXT.EXTENSION.REQUIRE_INSTALLATION_FF,
                  AdapterJS.TEXT.EXTENSION.BUTTON_FF,
                  'https://addons.mozilla.org/en-US/firefox/addon/skylink-webrtc-tools/', true, true);
              } else {
                failureCb(error);
              }
            });
          }
        }, 1);

      } else { // regular GetUserMediaRequest
        baseGetUserMedia(constraints, successCb, failureCb);
      }
    };

    AdapterJS.getUserMedia = window.getUserMedia = navigator.getUserMedia;
    /* Comment out to prevent recursive errors
    navigator.mediaDevices.getUserMedia = function(constraints) {
      return new Promise(function(resolve, reject) {
        window.getUserMedia(constraints, resolve, reject);
      });
    };*/

  } else if (window.navigator.webkitGetUserMedia && window.webrtcDetectedBrowser !== 'safari') {
    baseGetUserMedia = window.navigator.getUserMedia;

    navigator.getUserMedia = function (constraints, successCb, failureCb) {
      if (constraints && constraints.video && !!constraints.video.mediaSource) {
        if (window.webrtcDetectedBrowser !== 'chrome') {
          // This is Opera, which does not support screensharing
          failureCb(new Error('Current browser does not support screensharing'));
          return;
        }

        // would be fine since no methods
        var updatedConstraints = clone(constraints);

        var chromeCallback = function(error, sourceId) {
          if(!error) {
            updatedConstraints.video.mandatory = updatedConstraints.video.mandatory || {};
            updatedConstraints.video.mandatory.chromeMediaSource = 'desktop';
            updatedConstraints.video.mandatory.maxWidth = window.screen.width > 1920 ? window.screen.width : 1920;
            updatedConstraints.video.mandatory.maxHeight = window.screen.height > 1080 ? window.screen.height : 1080;

            if (sourceId) {
              updatedConstraints.video.mandatory.chromeMediaSourceId = sourceId;
            }

            delete updatedConstraints.video.mediaSource;

            baseGetUserMedia(updatedConstraints, successCb, failureCb);

          } else { // GUM failed
            if (error === 'permission-denied') {
              failureCb(new Error('Permission denied for screen retrieval'));
            } else {
              // NOTE(J-O): I don't think we ever pass in here.
              // A failure to capture the screen does not lead here.
              failureCb(new Error('Failed retrieving selected screen'));
            }
          }
        };

        var onIFrameCallback = function (event) {
          if (!event.data) {
            return;
          }

          if (event.data.chromeMediaSourceId) {
            if (event.data.chromeMediaSourceId === 'PermissionDeniedError') {
                chromeCallback('permission-denied');
            } else {
              chromeCallback(null, event.data.chromeMediaSourceId);
            }
          }

          if (event.data.chromeExtensionStatus) {
            if (event.data.chromeExtensionStatus === 'not-installed') {
              AdapterJS.renderNotificationBar(AdapterJS.TEXT.EXTENSION.REQUIRE_INSTALLATION_CHROME,
                AdapterJS.TEXT.EXTENSION.BUTTON_CHROME,
                event.data.data, true, true);
            } else {
              chromeCallback(event.data.chromeExtensionStatus, null);
            }
          }

          // this event listener is no more needed
          window.removeEventListener('message', onIFrameCallback);
        };

        window.addEventListener('message', onIFrameCallback);

        postFrameMessage({
          captureSourceId: true
        });

      } else {
        baseGetUserMedia(constraints, successCb, failureCb);
      }
    };

    AdapterJS.getUserMedia = window.getUserMedia = navigator.getUserMedia;
    navigator.mediaDevices.getUserMedia = function(constraints) {
      return new Promise(function(resolve, reject) {
        window.getUserMedia(constraints, resolve, reject);
      });
    };

  } else if (navigator.mediaDevices && navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)) {
    // nothing here because edge does not support screensharing
    console.warn('Edge does not support screensharing feature in getUserMedia');

  } else {
    baseGetUserMedia = window.navigator.getUserMedia;

    navigator.getUserMedia = function (constraints, successCb, failureCb) {
      if (constraints && constraints.video && !!constraints.video.mediaSource) {
        // would be fine since no methods
        var updatedConstraints = clone(constraints);

        // wait for plugin to be ready
        AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
          // check if screensharing feature is available
          if (!!AdapterJS.WebRTCPlugin.plugin.HasScreensharingFeature &&
            !!AdapterJS.WebRTCPlugin.plugin.isScreensharingAvailable) {
            // set the constraints
            updatedConstraints.video.optional = updatedConstraints.video.optional || [];
            updatedConstraints.video.optional.push({
              sourceId: AdapterJS.WebRTCPlugin.plugin.screensharingKey || 'Screensharing'
            });

            delete updatedConstraints.video.mediaSource;
          } else {
            failureCb(new Error('Your version of the WebRTC plugin does not support screensharing'));
            return;
          }
          baseGetUserMedia(updatedConstraints, successCb, failureCb);
        });
      } else {
        baseGetUserMedia(constraints, successCb, failureCb);
      }
    };

    AdapterJS.getUserMedia = getUserMedia =
       window.getUserMedia = navigator.getUserMedia;
    if ( navigator.mediaDevices &&
      typeof Promise !== 'undefined') {
      navigator.mediaDevices.getUserMedia = typeof requestUserMedia === 'undefined' ? undefined : requestUserMedia;
    }
  }

  // For chrome, use an iframe to load the screensharing extension
  // in the correct domain.
  // Modify here for custom screensharing extension in chrome
  if (window.webrtcDetectedBrowser === 'chrome') {
    var iframe = document.createElement('iframe');

    iframe.onload = function() {
      iframe.isLoaded = true;
    };

    iframe.src = 'https://cdn.temasys.com.sg/skylink/extensions/detectRTC.html';
    iframe.style.display = 'none';

    (document.body || document.documentElement).appendChild(iframe);

    var postFrameMessage = function (object) { // jshint ignore:line
      object = object || {};

      if (!iframe.isLoaded) {
        setTimeout(function () {
          iframe.contentWindow.postMessage(object, '*');
        }, 100);
        return;
      }

      iframe.contentWindow.postMessage(object, '*');
    };
  } else if (window.webrtcDetectedBrowser === 'opera') {
    console.warn('Opera does not support screensharing feature in getUserMedia');
  }
})();