RTCPeerConnection.addTrack and removeTrack added (behind flag)

chrome/test/data/webrtc/munge_sdp.js

Index: chrome/test/data/webrtc/munge_sdp.js
diff --git a/chrome/test/data/webrtc/munge_sdp.js b/chrome/test/data/webrtc/munge_sdp.js
index c2c7d9b6e86af648cc7a8bb16b42a4db3016e87f..f18a0ccb336e8a5e2f2a7f6d78d094ecdbd5c0d0 100644
--- a/chrome/test/data/webrtc/munge_sdp.js
+++ b/chrome/test/data/webrtc/munge_sdp.js
@@ -5,6 +5,66 @@
  */
 
 /**
+ * Parses the SDP to find all streams, tracks and stream-track relationships.
+ * Returns "{ streamIds, trackIds, streamTrackMap }" where |streamIds| and
+ * |trackIds| are |Set| of IDs and |streamTrackMap| is a string-set |Map| from
+ * stream IDs to track IDs (which tracks are members of which streams).
+ *
+ * @param {string} sdp
+ */
+function getSdpStreamsAndTracks(sdp) {

[Taylor_Brandstetter, 2017/07/06 22:45:14]

Relying on SDP parsing in this test is somewhat fragile (it will break when we
switch to "a=msid"); would it be possible to get the track/stream relationships
simply by seeing what remote streams are created on the "right tab" after
setting the remote description?

[hbos_chromium, 2017/07/07 12:07:48]

Good point. Done. Removed SDP usage from test, and added a test to check if
there is a remote stream containing a track with specified ids.

For the addTrack without a stream case the stream id is unknown without sdp
parsing, but we can still verify that some stream contain the track (before
addTrack with no stream is fixed not to create streams), and in both cases we
can make sure there is a receiver for the track.

+  let sdpLines = splitSdpLines(sdp);
+  let streamIds = new Set();
+  let trackIds = new Set();
+  // Find streams and tracks.
+  // a=ssrc:<ssrc> mslabel:<stream id>
+  // a=ssrc:<ssrc> label:<track id>
+  for (let lineNo = 0; lineNo = findLine(sdpLines, 'a=ssrc:', lineNo);
+       lineNo++) {
+    let line = sdpLines[lineNo];
+    let tokens = line.split(' ');
+    if (tokens.length !== 2)
+      continue;
+    if (tokens[1].startsWith('mslabel:')) {
+      streamIds.add(tokens[1].substring(8));
+    } else if (tokens[1].startsWith('label:')) {
+      trackIds.add(tokens[1].substring(6));
+    }
+  }
+  // Find stream and track relationships.
+  // a=ssrc:<ssrc> msid:<stream id> <track id>
+  let streamTrackMap = new Map();
+  for (let lineNo = 0; lineNo = findLine(sdpLines, 'a=ssrc:', lineNo);
+       lineNo++) {
+    let line = sdpLines[lineNo];
+    let tokens = line.split(' ');
+    if (tokens.length !== 3)
+      continue;
+    let ssrc = parseInt(tokens[0].substring(7));
+    if (!tokens[1].startsWith('msid:'))
+      failure('getSdpStreamsAndTracks', 'Expected \'msid:<stream id>\'.');
+    let streamId = tokens[1].substring(5);
+    if (!streamIds.has(streamId)) {
+      failure(
+          'getSdpStreamsAndTracks',
+          'Unknown stream ID \'' + streamId + '\' (\'mslabel\' line missing).');
+    }
+    let trackId = tokens[2];
+    if (!trackIds.has(trackId)) {
+      failure('getSdpStreamsAndTracks',
+              'Unknown track ID \'' + trackId + '\' (\'label\' line missing).');
+    }
+    if (!streamTrackMap.has(streamId))
+      streamTrackMap.set(streamId, new Set([ trackId ]));
+    else
+      streamTrackMap.get(streamId).add(trackId);
+  }
+  return { streamIds:streamIds,
+           trackIds:trackIds,
+           streamTrackMap:streamTrackMap };
+}
+
+/**
  * See |setSdpDefaultCodec|.
  */
 function setSdpDefaultAudioCodec(sdp, codec) {
@@ -29,7 +89,7 @@ function setOpusDtxEnabled(sdp) {
   var defaultCodec = getSdpDefaultAudioCodec(sdp);
   if (defaultCodec !== 'opus') {
     failure('setOpusDtxEnabled',
-             'Default audio codec is not set to \'opus\'.');
+            'Default audio codec is not set to \'opus\'.');
   }
 
   // Find codec ID for Opus, e.g. 111 if 'a=rtpmap:111 opus/48000/2'.
@@ -64,14 +124,15 @@ function setSdpDefaultCodec(sdp, type, codec) {
   // Find codec ID, e.g. 100 for 'VP8' if 'a=rtpmap:100 VP8/9000'.
   var codecId = findRtpmapId(sdpLines, codec);
   if (codecId === null) {
-    failure('sdpPreferCodec', 'Unknown ID for |codec| = \'' + codec + '\'.');
+    failure('setSdpDefaultCodec',
+            'Unknown ID for |codec| = \'' + codec + '\'.');
   }
 
   // Find 'm=|type|' line, e.g. 'm=video 9 UDP/TLS/RTP/SAVPF 100 101 107 116'.
   var mLineNo = findLine(sdpLines, 'm=' + type);
   if (mLineNo === null) {
     failure('setSdpDefaultCodec',
-             '\'m=' + type + '\' line missing from |sdp|.');
+            '\'m=' + type + '\' line missing from |sdp|.');
   }
 
   // Modify video line to use the desired codec as the default.
@@ -106,21 +167,21 @@ function getSdpDefaultCodec(sdp, type) {
   var mLineNo = findLine(sdpLines, 'm=' + type);
   if (mLineNo === null) {
     failure('getSdpDefaultCodec',
-             '\'m=' + type + '\' line missing from |sdp|.');
+            '\'m=' + type + '\' line missing from |sdp|.');
   }
 
   // The default codec's ID.
   var defaultCodecId = getMLineDefaultCodec(sdpLines[mLineNo]);
   if (defaultCodecId === null) {
     failure('getSdpDefaultCodec',
-             '\'m=' + type + '\' line contains no codecs.');
+            '\'m=' + type + '\' line contains no codecs.');
   }
 
   // Find codec name, e.g. 'VP8' for 100 if 'a=rtpmap:100 VP8/9000'.
   var defaultCodec = findRtpmapCodec(sdpLines, defaultCodecId);
   if (defaultCodec === null) {
     failure('getSdpDefaultCodec',
-             'Unknown codec name for default codec ' + defaultCodecId + '.');
+            'Unknown codec name for default codec ' + defaultCodecId + '.');
   }
   return defaultCodec;
 }
@@ -244,9 +305,9 @@ function mergeSdpLines(sdpLines) {
 }
 
 /** @private */
-function findLine(lines, startsWith) {
-  for (var i = 0; i < lines.length; i++) {
-    if (lines[i].startsWith(startsWith))
+function findLine(lines, lineStartsWith, startingLine = 0) {
+  for (var i = startingLine; i < lines.length; i++) {
+    if (lines[i].startsWith(lineStartsWith))
       return i;
   }
   return null;