MediaRecorder: make MediaRecorderHandler a MediaStreamObserver

content/renderer/media/media_recorder_handler.cc

Index: content/renderer/media/media_recorder_handler.cc
diff --git a/content/renderer/media/media_recorder_handler.cc b/content/renderer/media/media_recorder_handler.cc
index 2944013d3a50abb1f91a641ae9f62be14c338e4a..713d709c6137870d054858edbe1cbaf0daff765c 100644
--- a/content/renderer/media/media_recorder_handler.cc
+++ b/content/renderer/media/media_recorder_handler.cc
@@ -82,7 +82,7 @@ bool MediaRecorderHandler::canSupportMimeType(
 
 bool MediaRecorderHandler::initialize(
     blink::WebMediaRecorderHandlerClient* client,
-    const blink::WebMediaStream& media_stream,
+    const blink::WebMediaStream& web_media_stream,
     const blink::WebString& type,
     const blink::WebString& codecs) {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
@@ -96,10 +96,12 @@ bool MediaRecorderHandler::initialize(
     return false;
   }
   use_vp9_ = base::ToLowerASCII(codecs.utf8()).find("vp9") != std::string::npos;
-  media_stream_ = media_stream;
   DCHECK(client);
   client_ = client;
 
+  web_media_stream_ = web_media_stream;
+  MediaStream::GetMediaStream(web_media_stream)->AddObserver(this);
+
   return true;
 }
 
@@ -112,7 +114,7 @@ bool MediaRecorderHandler::start() {
 bool MediaRecorderHandler::start(int timeslice) {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
   DCHECK(!recording_);
-  DCHECK(!media_stream_.isNull());
+  DCHECK(!web_media_stream_.isNull());
   DCHECK(timeslice_.is_zero());
   DCHECK(!webm_muxer_);
 
@@ -120,8 +122,8 @@ bool MediaRecorderHandler::start(int timeslice) {
   slice_origin_timestamp_ = TimeTicks::Now();
 
   blink::WebVector<blink::WebMediaStreamTrack> video_tracks, audio_tracks;
-  media_stream_.videoTracks(video_tracks);
-  media_stream_.audioTracks(audio_tracks);
+  web_media_stream_.videoTracks(video_tracks);
+  web_media_stream_.audioTracks(audio_tracks);
 
   if (video_tracks.isEmpty() && audio_tracks.isEmpty()) {
     LOG(WARNING) << __FUNCTION__ << ": no media tracks.";
@@ -205,6 +207,15 @@ void MediaRecorderHandler::resume() {
     video_recorder->Resume();
 }
 
+void MediaRecorderHandler::TrackAdded(const blink::WebMediaStreamTrack& track) {
+  client_->onError("Track added");
+}
+
+void MediaRecorderHandler::TrackRemoved(
+    const blink::WebMediaStreamTrack& track) {
+  client_->onError("Track removed");
+}
+
 void MediaRecorderHandler::OnEncodedVideo(
     const scoped_refptr<media::VideoFrame>& video_frame,
     scoped_ptr<std::string> encoded_data,