Update MediaStreamTrack::Stop to latest draft.

content/test/data/media/getusermedia.html

Index: content/test/data/media/getusermedia.html
diff --git a/content/test/data/media/getusermedia.html b/content/test/data/media/getusermedia.html
index 7da11753b19c1a0b528772aa2cfce73275d93165..e0c9adf44dbd4301052a183f6633b63d84cf9d1d 100644
--- a/content/test/data/media/getusermedia.html
+++ b/content/test/data/media/getusermedia.html
@@ -157,9 +157,7 @@
   }
 
   // Creates two MediaStream and renders them locally. When the video of both
-  // streams are detected to be rolling, we stop the local stream. Since both
-  // streams have the same source, both video streams should stop. If they do,
-  // the test succeeds.
+  // streams are detected to be rolling, we stop the local video tracks.
   function twoGetUserMediaAndStop(constraints) {
     console.log('Calling Two GetUserMedia');
     navigator.webkitGetUserMedia(
@@ -173,18 +171,17 @@
           constraints,
           function(stream) {
             displayIntoVideoElement(stream,
-                stopStreamAndVerifyAllLocalViewsDontPlayVideo, 'local-view-2');
+                stopBothVideoTracksAndVerify(stream),

[phoglund_chromium, 2014/04/08 12:04:21]

This is wrong; you're supposed to pass in a callback as the second argument to
displayIntoVideoElement but you are making a function call which evaluates to
void. The only way this would be correct would be if stopBoth... was a higher
order function which returned a function itself, but that seems like fancy
stuff.

I think what you want is a closure like so:

function() {
  stopBoth..(stream);
}

[perkj_chrome, 2014/04/09 15:31:32]

Good catch

+                'local-view-2');
           },
           failedCallback);
     };
 
-    var stopStreamAndVerifyAllLocalViewsDontPlayVideo = function() {
-      gLocalStream.getVideoTracks()[0].stop();
-
-      // Since local-view and local-view-2 are playing the video from the same
-      // source, both of them should stop.
-      waitForVideoToStop('local-view');
+    var stopBothVideoTracksAndVerify = function(stream) {
       waitForVideoToStop('local-view-2');

[phoglund_chromium, 2014/04/08 12:04:21]

Hm. This is confusing, move the wait-for-video-to-stop to after the actual stop.
I don't think that can race.

[perkj_chrome, 2014/04/09 15:31:32]

Done.

+      stream.getVideoTracks()[0].stop();
+      // Make sure the original track is still playing and then stop it.

[phoglund_chromium, 2014/04/08 12:04:21]

So both tracks are no longer stopped by stopping their common source?

[perkj_chrome, 2014/04/09 15:31:32]

Right- stop is per track.

[phoglund_chromium, 2014/04/09 15:51:31]

Ok, so you're stopping video track 0 on #183, then you ensure gLocalStream is
still playing, after which you stop track 0 on that. So the stream you are
getting into this function is != gLocalStream because it comes from the second 
getUserMedia?

This is very confusing, I wonder if we can make it clearer. For instance rename
stream -> streamPlayingInLocalView2 or something like that, and add a comment
that gLocalStream is playing in local view 1.

We should think a bit about getting rid of the gLocalView global if we can; it's
really hard to use in the context where we have several active streams at once.

[perkj_chrome, 2014/04/10 11:25:08]

Done.

+      displayAndDetectVideo(gLocalStream, stopVideoTrack);
     };
   }