Implement disabling and enabling media tracks

media/mojo/interfaces/renderer.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module media.mojom;
 
 import "media/mojo/interfaces/demuxer_stream.mojom";
 import "media/mojo/interfaces/media_types.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
 interface Renderer {
   // Initializes the Renderer with one or both of an audio and video stream,
   // executing the callback with whether the initialization succeeded.
   Initialize(RendererClient client,
              DemuxerStream? audio,
              DemuxerStream? video) => (bool success);
 
   // Discards any buffered data, executing callback when completed.
   // NOTE: If an error occurs, RendererClient::OnError() can be called
   // before the callback is executed.
   Flush() => ();
 
   // Starts rendering from |time_usec|.
   StartPlayingFrom(int64 time_usec);
 
+  // Restarts rendering a given stream after it has been reenabled.
+  RestartStreamPlayback(bool video_stream, int64 time_usec);
+
   // Updates the current playback rate. The default playback rate should be 1.
   SetPlaybackRate(double playback_rate);
 
   // Sets the output volume. The default volume should be 1.
   SetVolume(float volume);
 
   // Attaches the CDM associated with |cdm_id| to the renderer service,
   // executing the callback with whether the CDM was successfully attached.
   SetCdm(int32 cdm_id) => (bool success);
 };
@@ skipping 17 matching lines @@
   // this error happens during an operation that has a completion callback,
   // OnError() will be called before firing the completion callback.
   OnError();
 
   // Executed for the first video frame and whenever natural size changes.
   OnVideoNaturalSizeChange(mojo.Size size);
 
   // Executed for the first video frame and whenever opacity changes.
   OnVideoOpacityChange(bool opaque);
 };