Implement disabling and enabling media tracks

media/mojo/services/mojo_renderer_impl.cc

Index: media/mojo/services/mojo_renderer_impl.cc
diff --git a/media/mojo/services/mojo_renderer_impl.cc b/media/mojo/services/mojo_renderer_impl.cc
index 6f028c877e71c479611e5535f75dc93b1aa9f857..6e013a9d05b248e11a1ee361a3b852d879d7319e 100644
--- a/media/mojo/services/mojo_renderer_impl.cc
+++ b/media/mojo/services/mojo_renderer_impl.cc
@@ -124,6 +124,14 @@ void MojoRendererImpl::StartPlayingFrom(base::TimeDelta time) {
   remote_renderer_->StartPlayingFrom(time.InMicroseconds());
 }
 
+void MojoRendererImpl::RestartStreamPlayback(DemuxerStream* stream,
+                                             base::TimeDelta time) {
+  DVLOG(2) << __FUNCTION__;
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  bool video_stream = (stream->type() == DemuxerStream::VIDEO);
+  remote_renderer_->RestartStreamPlayback(video_stream, time.InMicroseconds());
+}
+
 void MojoRendererImpl::SetPlaybackRate(double playback_rate) {
   DVLOG(2) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());