VIDEO-4958 Remove unused Chrome shims and plan-b shims.

lib/connect.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const { MediaStreamTrack } = require('./webrtc');
 const { guessBrowser, guessBrowserVersion } = require('./webrtc/util');
 const createCancelableRoomPromise = require('./cancelableroompromise');
 const EncodingParametersImpl = require('./encodingparameters');

lib/createlocaltracks.ts

@@ -13,7 +13,7 @@ import {
 import { applyNoiseCancellation } from './media/track/noisecancellationimpl';
 
 const { buildLogLevels } = require('./util');
-const { getUserMedia, MediaStreamTrack } = require('./webrtc');
+const { getUserMedia } = require('./webrtc');
 
 const {
   LocalAudioTrack,

lib/localparticipant.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const { MediaStreamTrack } = require('./webrtc');
 const { asLocalTrack, asLocalTrackPublication, trackClass } = require('./util');
 const { typeErrors: E, trackPriority } = require('./util/constants');
 const { validateLocalTrack } = require('./util/validate');

lib/media/track/mediatrack.js

@@ -1,8 +1,6 @@
 'use strict';
 
 const { isIOS } = require('../../util/browserdetection');
-const { MediaStream } = require('../../webrtc');
-
 const { waitForEvent, waitForSometime } = require('../../util');
 const localMediaRestartDeferreds = require('../../util/localmediarestartdeferreds');
 const Track = require('./');

lib/signaling/v2/peerconnection.js

@@ -1,10 +1,9 @@
 'use strict';
 
 const DefaultBackoff = require('../../util/backoff');
+
 const {
-  RTCIceCandidate: DefaultRTCIceCandidate,
   RTCPeerConnection: DefaultRTCPeerConnection,
-  RTCSessionDescription: DefaultRTCSessionDescription,
   getStats: getStatistics
 } = require('../../webrtc');
 
@@ -128,9 +127,9 @@ class PeerConnectionV2 extends StateMachine {
       setSimulcast,
       Backoff: DefaultBackoff,
       IceConnectionMonitor: DefaultIceConnectionMonitor,
-      RTCIceCandidate: DefaultRTCIceCandidate,
+      RTCIceCandidate,
       RTCPeerConnection: DefaultRTCPeerConnection,
-      RTCSessionDescription: DefaultRTCSessionDescription,
+      RTCSessionDescription,
       Timeout: DefaultTimeout
     }, options);
 

lib/util/sdp/issue8329.js

@@ -1,7 +1,5 @@
 'use strict';
 
-const { RTCSessionDescription } = require('../../webrtc');
-
 const { createPtToCodecName, getMediaSections } = require('./');
 
 /**

lib/util/support.js

@@ -1,7 +1,8 @@
+/* globals RTCRtpTransceiver */
+
 'use strict';
 
 const { guessBrowser, support: isWebRTCSupported } = require('../webrtc/util');
-const { getSdpFormat } = require('../webrtc/util/sdp');
 const { isAndroid, isMobile, isNonChromiumEdge, rebrandedChromeBrowser, mobileWebKitBrowser } = require('./browserdetection');
 
 const SUPPORTED_CHROME_BASED_BROWSERS = [
@@ -22,11 +23,56 @@ const SUPPORTED_IOS_BROWSERS = [
 // Currently none. Add 'brave', 'edg', and 'edge' here once we start supporting them
 const SUPPORTED_MOBILE_WEBKIT_BASED_BROWSERS = [];
 
+// NOTE(mmalavalli): We cache Chrome's unified plan support in order
+// to prevent instantiation of more than one RTCPeerConnection.
+let isChromeUnifiedPlanSupported;
+
+/**
+ * Check whether the current browser supports unified plan sdps.
+ * @param {boolean} [shouldCacheResultForChrome=true] - For unit tests only
+ */
+function isUnifiedPlanSupported(shouldCacheResultForChrome = true) {
+  const maybeCacheResultForChrome = shouldCacheResultForChrome
+    ? result => { isChromeUnifiedPlanSupported = result; }
+    : () => { /* Do not cache result for Chrome */ };
+
+  let isSupported;
+
+  return ({
+    chrome: () => {
+      if (typeof isChromeUnifiedPlanSupported === 'boolean') {
+        return isChromeUnifiedPlanSupported;
+      }
+      if (typeof RTCPeerConnection === 'undefined' || !('addTransceiver' in RTCPeerConnection.prototype)) {
+        maybeCacheResultForChrome(isSupported = false);
+        return isSupported;
+      }
+      const peerConnection = new RTCPeerConnection();
+      try {
+        peerConnection.addTransceiver('audio');
+        maybeCacheResultForChrome(isSupported = true);
+      } catch (e) {
+        maybeCacheResultForChrome(isSupported = false);
+      }
+      peerConnection.close();
+      return isSupported;
+    },
+    firefox: () => {
+      return true;
+    },
+    safari: () => {
+      return typeof RTCRtpTransceiver !== 'undefined'
+        && 'currentDirection' in RTCRtpTransceiver.prototype;
+    }
+  }[guessBrowser()] || (() => false))();
+}
+
 /**
  * Check if the current browser is officially supported by twilio-video.js.
+ @param {boolean} [shouldCacheUnifiedPlanSupportForChrome=true] - For unit tests only
  * @returns {boolean}
  */
-function isSupported() {
+function isSupported(shouldCacheUnifiedPlanSupportForChrome = true) {
   const browser = guessBrowser();
 
   // NOTE (csantos): Return right away if there is no browser detected
@@ -42,7 +88,7 @@ function isSupported() {
 
   return !!browser
     && isWebRTCSupported()
-    && getSdpFormat() === 'unified'
+    && isUnifiedPlanSupported(shouldCacheUnifiedPlanSupportForChrome)
     && (!rebrandedChrome || SUPPORTED_CHROME_BASED_BROWSERS.includes(rebrandedChrome))
     && !isNonChromiumEdge(browser)
     && (!mobileWebKit || SUPPORTED_MOBILE_WEBKIT_BASED_BROWSERS.includes(mobileWebKit))

lib/webrtc/getstats.js

@@ -1,7 +1,6 @@
 'use strict';
 
 const { flatMap, guessBrowser, guessBrowserVersion } = require('./util');
-const { getSdpFormat } = require('./util/sdp');
 
 const guess = guessBrowser();
 const guessVersion = guessBrowserVersion();
@@ -277,14 +276,9 @@ function standardizeFirefoxActiveIceCandidatePairStats(stats) {
  */
 function getTracks(peerConnection, kind, localOrRemote) {
   const getSendersOrReceivers = localOrRemote === 'local' ? 'getSenders' : 'getReceivers';
-  if (peerConnection[getSendersOrReceivers]) {
-    return peerConnection[getSendersOrReceivers]()
-      .map(({ track }) => track)
-      .filter(track => track && track.kind === kind);
-  }
-  const getStreams = localOrRemote === 'local' ? 'getLocalStreams' : 'getRemoteStreams';
-  const getTracks = kind === 'audio' ? 'getAudioTracks' : 'getVideoTracks';
-  return flatMap(peerConnection[getStreams](), stream => stream[getTracks]());
+  return peerConnection[getSendersOrReceivers]()
+    .map(({ track }) => track)
+    .filter(track => track && track.kind === kind);
 }
 
 /**
@@ -298,20 +292,11 @@ function getTrackStats(peerConnection, track, options = {}) {
   if (typeof options.testForChrome !== 'undefined' || isChrome) {
     return chromeOrSafariGetTrackStats(peerConnection, track);
   }
-  if (typeof options.testForFirefox  !== 'undefined' || isFirefox) {
+  if (typeof options.testForFirefox !== 'undefined' || isFirefox) {
     return firefoxGetTrackStats(peerConnection, track, options.isRemote);
   }
-  if (typeof options.testForSafari  !== 'undefined' || isSafari) {
-    if (typeof options.testForSafari  !== 'undefined' || getSdpFormat() === 'unified') {
-      return chromeOrSafariGetTrackStats(peerConnection, track);
-    }
-    // NOTE(syerrapragada): getStats() is not supported on
-    // Safari versions where plan-b is the SDP format
-    // due to this bug: https://bugs.webkit.org/show_bug.cgi?id=192601
-    return Promise.reject(new Error([
-      'getStats() is not supported on this version of Safari',
-      'due to this bug: https://bugs.webkit.org/show_bug.cgi?id=192601'
-    ].join(' ')));
+  if (typeof options.testForSafari !== 'undefined' || isSafari) {
+    return chromeOrSafariGetTrackStats(peerConnection, track);
   }
   return Promise.reject(new Error('RTCPeerConnection#getStats() not supported'));
 }

lib/webrtc/index.js

@@ -11,25 +11,9 @@ Object.defineProperties(WebRTC, {
     enumerable: true,
     value: require('./getusermedia')
   },
-  MediaStream: {
-    enumerable: true,
-    value: require('./mediastream')
-  },
-  MediaStreamTrack: {
-    enumerable: true,
-    value: require('./mediastreamtrack')
-  },
-  RTCIceCandidate: {
-    enumerable: true,
-    value: require('./rtcicecandidate')
-  },
   RTCPeerConnection: {
     enumerable: true,
     value: require('./rtcpeerconnection')
-  },
-  RTCSessionDescription: {
-    enumerable: true,
-    value: require('./rtcsessiondescription')
   }
 });