Cast: Add JS API to get raw events logs from cast extension.

chrome/renderer/media/cast_rtp_stream.h

Index: chrome/renderer/media/cast_rtp_stream.h
diff --git a/chrome/renderer/media/cast_rtp_stream.h b/chrome/renderer/media/cast_rtp_stream.h
index f3a06c0e317108a6d55607a4da294acf1c845526..173fee0fdb176509faf3bb64c566d25a4a9c18c7 100644
--- a/chrome/renderer/media/cast_rtp_stream.h
+++ b/chrome/renderer/media/cast_rtp_stream.h
@@ -117,6 +117,15 @@ class CastRtpStream {
   // Stop encoding.
   void Stop();
 
+  void SetStreamId(const int stream_id);
+
+  // Sets up event subscribers for events for this stream.
+  void StartLogging();
+
+  // Get serialized raw events for this stream and invokes |callback|
+  // with the result.
+  void GetRawEvents(base::Callback<void(scoped_ptr<std::string>)> callback);
+
  private:
   // Return true if this track is an audio track. Return false if this
   // track is a video track.
@@ -129,6 +138,7 @@ class CastRtpStream {
   scoped_ptr<CastAudioSink> audio_sink_;
   scoped_ptr<CastVideoSink> video_sink_;
   CastRtpParams params_;
+  int stream_id_;
   base::WeakPtrFactory<CastRtpStream> weak_factory_;
   base::Closure stop_callback_;
   ErrorCallback error_callback_;