Implement disabling and enabling media tracks

media/renderers/renderer_impl.h

Index: media/renderers/renderer_impl.h
diff --git a/media/renderers/renderer_impl.h b/media/renderers/renderer_impl.h
index 9eb1d4f6e650e9f840832e751fc476c31653a4e0..76c62c263bd799944390aa89776866070cffac52 100644
--- a/media/renderers/renderer_impl.h
+++ b/media/renderers/renderer_impl.h
@@ -56,6 +56,7 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
               const CdmAttachedCB& cdm_attached_cb) final;
   void Flush(const base::Closure& flush_cb) final;
   void StartPlayingFrom(base::TimeDelta time) final;
+  void RestartStreamPlayback(DemuxerStream* stream, base::TimeDelta time) final;
   void SetPlaybackRate(double playback_rate) final;
   void SetVolume(float volume) final;
   base::TimeDelta GetMediaTime() final;
@@ -103,6 +104,9 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   void FlushVideoRenderer();
   void OnVideoRendererFlushDone();
 
+  void OnAudioRendererFlushDone_ForRestart(base::TimeDelta time);
+  void OnVideoRendererFlushDone_ForRestart(base::TimeDelta time);
+
   // Callback executed by filters to update statistics.
   void OnStatisticsUpdate(const PipelineStatistics& stats);
 
@@ -178,6 +182,9 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   // runs out of data but the audio renderer still has enough.
   base::TimeDelta video_underflow_threshold_;
 
+  bool restarting_audio_ = false;
+  bool restarting_video_ = false;
+
   base::WeakPtr<RendererImpl> weak_this_;
   base::WeakPtrFactory<RendererImpl> weak_factory_;