Refactor MediaStreamTrack video onmute event.

content/renderer/media/media_stream_track.cc

Index: content/renderer/media/media_stream_track.cc
diff --git a/content/renderer/media/media_stream_track.cc b/content/renderer/media/media_stream_track.cc
index 9aca963af4f47bd57b38834975700a256ce964fd..1b11bbaa3af9b2def1cb383ad5f707cd31684221 100644
--- a/content/renderer/media/media_stream_track.cc
+++ b/content/renderer/media/media_stream_track.cc
@@ -20,8 +20,7 @@ MediaStreamTrack* MediaStreamTrack::GetTrack(
 MediaStreamTrack::MediaStreamTrack(
     webrtc::MediaStreamTrackInterface* track, bool is_local_track)
     : track_(track),
-      muted_state_(false),
-      is_local_track_(is_local_track){
+      is_local_track_(is_local_track) {
 }
 
 MediaStreamTrack::~MediaStreamTrack() {
@@ -33,16 +32,6 @@ void MediaStreamTrack::SetEnabled(bool enabled) {
     track_->set_enabled(enabled);
 }
 
-void MediaStreamTrack::SetMutedState(bool muted_state) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  muted_state_ = muted_state;
-}
-
-bool MediaStreamTrack::GetMutedState(void) const {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  return muted_state_;
-}
-
 void MediaStreamTrack::Stop() {
   DCHECK(thread_checker_.CalledOnValidThread());
   // Stop means that a track should be stopped permanently. But