Implement disabling and enabling media tracks

media/mojo/services/mojo_demuxer_stream_adapter.cc

Index: media/mojo/services/mojo_demuxer_stream_adapter.cc
diff --git a/media/mojo/services/mojo_demuxer_stream_adapter.cc b/media/mojo/services/mojo_demuxer_stream_adapter.cc
index 9d540c60a3e5590c0fcd4afd75edf04f024e45dd..82c9f781a593e5fa0bb370ee8a691a88d9512498 100644
--- a/media/mojo/services/mojo_demuxer_stream_adapter.cc
+++ b/media/mojo/services/mojo_demuxer_stream_adapter.cc
@@ -70,6 +70,29 @@ VideoRotation MojoDemuxerStreamAdapter::video_rotation() {
   return VIDEO_ROTATION_0;
 }
 
+#if DCHECK_IS_ON()
+void DcheckRemoteEnabledValue(bool local_enabled_value,
+                              bool remote_enabled_value) {
+  DCHECK_EQ(local_enabled_value, remote_enabled_value);
+}
+#endif
+
+bool MojoDemuxerStreamAdapter::enabled() const {
+#if DCHECK_IS_ON()
+  // TODO(servolk): Is it worth waiting for the IPC call roundtrip, when we can
+  // just maintain the current |enabled_| status in here. Would this cause any
+  // problems?
+  demuxer_stream_->enabled(base::Bind(&DcheckRemoteEnabledValue, enabled_));
+#endif
+  return enabled_;
+}
+
+void MojoDemuxerStreamAdapter::set_enabled(bool enabled,
+                                           base::TimeDelta timestamp) {
+  demuxer_stream_->set_enabled(enabled, timestamp.InMicroseconds());
+  enabled_ = enabled;
+}
+
 // TODO(xhwang): Pass liveness here.
 void MojoDemuxerStreamAdapter::OnStreamReady(
     mojom::DemuxerStream::Type type,