Move passing of WebRTC rendering frames to IO thread

content/renderer/media/webmediaplayer_ms.h

 // Copyright 2013 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.
 
 #ifndef CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_MS_H_
 #define CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_MS_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 56 matching lines @@
       public NON_EXPORTED_BASE(base::SupportsWeakPtr<WebMediaPlayerMS>) {
  public:
   // Construct a WebMediaPlayerMS with reference to the client, and
   // a MediaStreamClient which provides MediaStreamVideoRenderer.
   WebMediaPlayerMS(
       blink::WebFrame* frame,
       blink::WebMediaPlayerClient* client,
       base::WeakPtr<media::WebMediaPlayerDelegate> delegate,
       media::MediaLog* media_log,
       std::unique_ptr<MediaStreamRendererFactory> factory,
-      const scoped_refptr<base::SingleThreadTaskRunner>& compositor_task_runner,
-      const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
-      const scoped_refptr<base::TaskRunner>& worker_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_,
+      scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner,
+      scoped_refptr<base::SingleThreadTaskRunner> media_task_runner,
+      scoped_refptr<base::TaskRunner> worker_task_runner,
       media::GpuVideoAcceleratorFactories* gpu_factories,
       const blink::WebString& sink_id,
       const blink::WebSecurityOrigin& security_origin);
 
   ~WebMediaPlayerMS() override;
 
   void load(LoadType load_type,
             const blink::WebMediaPlayerSource& source,
             CORSMode cors_mode) override;
 
@@ skipping 116 matching lines @@
   scoped_refptr<MediaStreamAudioRenderer> audio_renderer_; // Weak
   media::SkCanvasVideoRenderer video_renderer_;
 
   bool paused_;
   media::VideoRotation video_rotation_;
 
   scoped_refptr<media::MediaLog> media_log_;
 
   std::unique_ptr<MediaStreamRendererFactory> renderer_factory_;
 
+  const scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+  const scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner_;
   const scoped_refptr<base::SingleThreadTaskRunner> media_task_runner_;
   const scoped_refptr<base::TaskRunner> worker_task_runner_;
   media::GpuVideoAcceleratorFactories* gpu_factories_;
 
   // Used for DCHECKs to ensure methods calls executed in the correct thread.
   base::ThreadChecker thread_checker_;
 
-  // WebMediaPlayerMS owns |compositor_| and destroys it on
-  // |compositor_task_runner_|.
-  std::unique_ptr<WebMediaPlayerMSCompositor> compositor_;
-
-  const scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner_;
+  scoped_refptr<WebMediaPlayerMSCompositor> compositor_;
 
   const std::string initial_audio_output_device_id_;
   const url::Origin initial_security_origin_;
 
   // The last volume received by setVolume() and the last volume multiplier from
   // OnVolumeMultiplierUpdate().  The multiplier is typical 1.0, but may be less
   // if the WebMediaPlayerDelegate has requested a volume reduction (ducking)
   // for a transient sound.  Playout volume is derived by volume * multiplier.
   double volume_;
   double volume_multiplier_;
 
   // True if playback should be started upon the next call to OnShown(). Only
   // used on Android.
   bool should_play_upon_shown_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerMS);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_MS_H_