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..b9b11a3356d5f51775da6276fc8a63ac4a55025a 100644
--- a/media/renderers/renderer_impl.h
+++ b/media/renderers/renderer_impl.h
@@ -62,6 +62,8 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   bool HasAudio() final;
   bool HasVideo() final;
 
+  void RestartStreamPlayback(DemuxerStream* stream, base::TimeDelta time);
+
   // Helper functions for testing purposes. Must be called before Initialize().
   void DisableUnderflowForTesting();
   void EnableClocklessVideoPlaybackForTesting();
@@ -103,6 +105,9 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   void FlushVideoRenderer();
   void OnVideoRendererFlushDone();
 
+  void RestartAudioRenderer(base::TimeDelta time);
+  void RestartVideoRenderer(base::TimeDelta time);
+
   // Callback executed by filters to update statistics.
   void OnStatisticsUpdate(const PipelineStatistics& stats);
 
@@ -174,10 +179,16 @@ class MEDIA_EXPORT RendererImpl : public Renderer {
   // Used to defer underflow for video when audio is present.
   base::CancelableClosure deferred_underflow_cb_;
 
+  // Used to defer underflow for audio when restarting audio playback.
+  base::CancelableClosure deferred_audio_restart_underflow_cb_;
+
   // The amount of time to wait before declaring underflow if the video 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_;