Add MediaStreamSource frame rate calculation to the tracker.

content/renderer/media/webrtc/media_stream_remote_video_source.cc

Index: content/renderer/media/webrtc/media_stream_remote_video_source.cc
diff --git a/content/renderer/media/webrtc/media_stream_remote_video_source.cc b/content/renderer/media/webrtc/media_stream_remote_video_source.cc
index f912cd592350ce495cb6a7a4fc6d791fe419bc14..ef74bf986617ed5280e3066722c28cbbf314c38e 100644
--- a/content/renderer/media/webrtc/media_stream_remote_video_source.cc
+++ b/content/renderer/media/webrtc/media_stream_remote_video_source.cc
@@ -17,6 +17,8 @@
 
 namespace content {
 
+const char kTypeName[] = "Remote Video";
+
 // Internal class used for receiving frames from the webrtc track on a
 // libjingle thread and forward it to the IO-thread.
 class MediaStreamRemoteVideoSource::RemoteVideoSourceDelegate
@@ -163,6 +165,10 @@ void MediaStreamRemoteVideoSource::StopSourceImpl() {
   remote_track_->RemoveRenderer(delegate_.get());
 }
 
+std::string MediaStreamRemoteVideoSource::TypeName() const {
+  return kTypeName;
+}
+
 webrtc::VideoRendererInterface*
 MediaStreamRemoteVideoSource::RenderInterfaceForTest() {
   return delegate_.get();