Move passing of WebRTC rendering frames to IO thread

content/shell/renderer/layout_test/test_media_stream_video_renderer.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_SHELL_RENDERER_LAYOUT_TEST_TEST_MEDIA_STREAM_VIDEO_RENDERER_H_
 #define CONTENT_SHELL_RENDERER_LAYOUT_TEST_TEST_MEDIA_STREAM_VIDEO_RENDERER_H_
 
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "content/public/renderer/media_stream_video_renderer.h"
 #include "ui/gfx/geometry/size.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace content {
 
 // A MediaStreamVideoRenderer that generates raw frames and
 // passes them to webmediaplayer.
 // Since non-black pixel values are required in the layout test, e.g.,
 // media/video-capture-canvas.html, this class should generate frame with
 // only non-black pixels.
 class TestMediaStreamVideoRenderer : public MediaStreamVideoRenderer {
  public:
   TestMediaStreamVideoRenderer(
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
       const gfx::Size& size,
       const base::TimeDelta& frame_duration,
       const base::Closure& error_cb,
       const RepaintCB& repaint_cb);
 
   // MediaStreamVideoRenderer implementation.
   void Start() override;
   void Stop() override;
   void Resume() override;
   void Pause() override;
 
  protected:
   ~TestMediaStreamVideoRenderer() override;
 
  private:
   enum State {
     kStarted,
     kPaused,
     kStopped,
   };
 
   void GenerateFrame();
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
   gfx::Size size_;
   State state_;
 
   base::TimeDelta current_time_;
   base::TimeDelta frame_duration_;
   base::Closure error_cb_;
   RepaintCB repaint_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(TestMediaStreamVideoRenderer);
 };
 
 } // namespace content
 
 #endif // CONTENT_SHELL_RENDERER_LAYOUT_TEST_TEST_MEDIA_STREAM_VIDEO_RENDERER_H_