Implement a source for remote video tracks.

content/renderer/media/mock_media_stream_dependency_factory.cc

Index: content/renderer/media/mock_media_stream_dependency_factory.cc
diff --git a/content/renderer/media/mock_media_stream_dependency_factory.cc b/content/renderer/media/mock_media_stream_dependency_factory.cc
index 92192b94cd40fc1bb50871566bacd3869068302d..65c2c328c0a0975bfe840b9e451bbe6bdc82c764 100644
--- a/content/renderer/media/mock_media_stream_dependency_factory.cc
+++ b/content/renderer/media/mock_media_stream_dependency_factory.cc
@@ -292,17 +292,20 @@ MockLocalVideoTrack::MockLocalVideoTrack(std::string id,
       id_(id),
       state_(MediaStreamTrackInterface::kLive),
       source_(source),
-      observer_(NULL) {
+      observer_(NULL),
+      renderer_(NULL) {
 }
 
 MockLocalVideoTrack::~MockLocalVideoTrack() {}
 
 void MockLocalVideoTrack::AddRenderer(VideoRendererInterface* renderer) {
-  NOTIMPLEMENTED();
+  DCHECK(!renderer_);
+  renderer_ = renderer;
 }
 
 void MockLocalVideoTrack::RemoveRenderer(VideoRendererInterface* renderer) {

[Jói, 2014/03/17 22:00:40]

The interface here is a little weird unless you plan to allow multiple renderers
in the future. If it's just the one renderer, then a SetRenderer would seem
simpler.

[perkj_chrome, 2014/03/19 16:34:48]

This is an overriden method. The real implementation in libjingle support
multiple but since I only need one renderer I DCHECK that is how I used it 
instead. I renamed this class to indicate what it really is.

-  NOTIMPLEMENTED();
+  DCHECK_EQ(renderer_, renderer);
+  renderer_ = NULL;
 }
 
 std::string MockLocalVideoTrack::kind() const {