Added implementation of RemoteMediaStreams.

content/test/data/media/peerconnection-call.html

Index: content/test/data/media/peerconnection-call.html
diff --git a/content/test/data/media/peerconnection-call.html b/content/test/data/media/peerconnection-call.html
index 39b01b5a5f0a926c0e4d9e58fdd904bdb98cd6c2..758ebad73fe071d53573fb69afc44779bfbf3970 100644
--- a/content/test/data/media/peerconnection-call.html
+++ b/content/test/data/media/peerconnection-call.html
@@ -113,6 +113,68 @@
     waitForVideo('remote-view-1');
     waitForVideo('remote-view-2');
   }
+      
+  // Test call with a new Video MediaStream that has been created based on a 
+  // stream generated by getUserMedia. When Video is flowing, an audio track 
+  // is added to the sent stream and the video track is removed. This
+  // is to test that adding and removing of remote tracks on an existing 
+  // mediastream works.
+  function callWithNewVideoMediaStreamLaterSwitchToAudio() {
+    createConnections(null);
+    navigator.webkitGetUserMedia({audio:true, video:true},

[phoglund_chromium, 2013/04/16 14:44:58]

Nit: line length

[perkj_chrome, 2013/04/18 14:46:58]

Done.

+        createNewVideoStreamAndAddToBothConnections, printGetUserMediaError);        
+        
+    waitForVideo('remote-view-1');
+    waitForVideo('remote-view-2');
+    
+    // Set an event handler for when video is playing.

[phoglund_chromium, 2013/04/16 14:44:58]

Side note:  We should consider if we make this event handling framework clearer.
It would be better in this case if we could say something like
whenVideoIsPlaying(function() { ... }); instead of setAllEventsOccurredHandler,
which is less clear. We don't have to do it now though.

[perkj_chrome, 2013/04/18 14:46:58]

I was considering that. But one feature I like with this is that you can setup
multiple events to occur and don't care about the order. 

If you do care about the order you just change setAllEventsOccuredHandler after
every step.  So it has pros and cons.

+    setAllEventsOccuredHandler(function() {
+      // Add an audio track to the local stream and remove the video track.
+      local_stream = gFirstConnection.getLocalStreams()[0];
+      local_stream.addTrack(gLocalStream.getAudioTracks()[0]);
+      local_stream.removeTrack(local_stream.getVideoTracks()[0]);
+            
+      remote_stream_1 = gFirstConnection.getRemoteStreams()[0];
+      // Add an expected event that onaddtrack will be called on the remote

[phoglund_chromium, 2013/04/16 14:44:58]

So you call addTrack and removeTrack and _later_ set up the expectations related
to them? I guess the thing that makes it work is that this function will finish
executing before any callbacks get a chance to run, but I think it makes more
sense from a code perspective to call the add and remove functions as the last
thing you do rather than the first.

[perkj_chrome, 2013/04/18 14:46:58]

Nothing happens until you do the renegotiation. That said- I will move add and
remove tracks anyway.

+      // mediastream received on gFirstConnection when the audio track is 
+      // received.       
+      addExpectedEvent();      
+      remote_stream_1.onaddtrack = function() {
+        expectEquals(remote_stream_1.getAudioTracks()[0].id,
+                     local_stream.getAudioTracks()[0].id); 
+        eventOccured();
+      }
+      
+      // Add an expectation that the received video track is removed from 
+      // gFirstConnection.
+      addExpectedEvent();            
+      remote_stream_1.onremovetrack = function() {
+        eventOccured();      
+      }
+      
+      // Add an expected event that onaddtrack will be called on the remote
+      // mediastream received on gSecondConnection when the audio track is 
+      // received.       
+      remote_stream_2 = gSecondConnection.getRemoteStreams()[0];      
+      addExpectedEvent();
+      remote_stream_2.onaddtrack = function() {
+        expectEquals(remote_stream_2.getAudioTracks()[0].id,
+                     local_stream.getAudioTracks()[0].id); 
+        eventOccured();        
+      }            
+      
+      // Add an expectation that the received video track is removed from 
+      // gSecondConnection.
+      addExpectedEvent();            
+      remote_stream_2.onremovetrack = function() {
+        eventOccured();      
+      }
+      
+      // When all the above events have occurred- the test pass.
+      setAllEventsOccuredHandler(function() { document.title = 'OK'; });
+      negotiate();      
+    });
+  }
 
   // This function is used for setting up a test that:
   // 1. Creates a data channel on |gFirstConnection| and sends data to
@@ -212,9 +274,12 @@
   // MediaStream. A new MediaStream is created and the video track from 
   // |localStream| is added.
   function createNewVideoStreamAndAddToBothConnections(localStream) {
-    var new_stream = new webkitMediaStream();
+    displayAndRemember(localStream);

[phoglund_chromium, 2013/04/16 14:44:58]

This change doesn't make sense, accidental?

[perkj_chrome, 2013/04/18 14:46:58]

Nope- I want to reuse createNewVideoStreamAndAddToBothConnections. ButI wanted
to makes sure gLocalStream is set to what getusermedia returns. 
So therefore copied what I needed from addStreamToBothConnectionsAndNegotiate
here instead.

+    var new_stream = new webkitMediaStream();    
     new_stream.addTrack(localStream.getVideoTracks()[0]);    
-    addStreamToBothConnectionsAndNegotiate(new_stream);
+    gFirstConnection.addStream(new_stream);
+    gSecondConnection.addStream(new_stream);
+    negotiate();
   }
 
   function negotiate() {