Connect the new video rendering path to the compositor.

media/renderers/video_renderer_impl.h

Index: media/renderers/video_renderer_impl.h
diff --git a/media/renderers/video_renderer_impl.h b/media/renderers/video_renderer_impl.h
index 7eb9814204eb61b1bd2c04c8d02c1a1ac87e7c4f..1a4f964d6ab8b206a377cf2c236693965f400437 100644
--- a/media/renderers/video_renderer_impl.h
+++ b/media/renderers/video_renderer_impl.h
@@ -14,6 +14,7 @@
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"
+#include "base/timer/timer.h"
 #include "media/base/decryptor.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/media_log.h"
@@ -23,6 +24,7 @@
 #include "media/base/video_renderer.h"
 #include "media/base/video_renderer_sink.h"
 #include "media/filters/decoder_stream.h"
+#include "media/filters/video_renderer_algorithm.h"
 
 namespace base {
 class SingleThreadTaskRunner;
@@ -79,6 +81,12 @@ class MEDIA_EXPORT VideoRendererImpl
                                    base::TimeTicks deadline_max) override;
   void OnFrameDropped() override;
 
+  void enable_new_video_renderer_for_testing() {
+    use_new_video_renderering_path_ = true;
+  }
+
+  void SetBackgroundRenderingForTesting(bool enabled, base::TimeDelta timeout);

[xhwang, 2015/04/29 06:51:55]

nit: Add comment, or s/timeout/background_rendering_timeout/ to make it self
explanatory.

[DaleCurtis, 2015/04/30 03:49:37]

Done.

+
  private:
   // Creates a dedicated |thread_| for video rendering.
   void CreateVideoThread();
@@ -123,8 +131,42 @@ class MEDIA_EXPORT VideoRendererImpl
   // |wait_duration|.
   void UpdateStatsAndWait_Locked(base::TimeDelta wait_duration);
 
+  // Called after we've painted the first frame.  If |time_progressing_| is
+  // false it Stop() on |sink_|.
+  void MaybeStopSinkAfterFirstPaint();
+
+  // Resets and primes the |background_rendering_timer_|, when the timer fires
+  // it calls the BackgroundRender() method below.
+  void RestartBackgroundRenderTimer();
+
+  // Called by |background_rendering_timer_| when enough time elapses where we
+  // haven't seen a Render() call.
+  void BackgroundRender();
+  void BackgroundRender_Locked();
+
+  // Return true if there is no more room for additional buffered frames.

[xhwang, 2015/04/29 06:51:55]

nit: Return_s_

[DaleCurtis, 2015/04/30 03:49:37]

Done.

+  bool HaveReachedBufferingCap();
+
+  // Starts or stops |sink_| respectively. Do not call while |lock_| is held.
+  void StartSink();
+  void StopSink();
+
+  // Fires |ended_cb_| if there are no remaining usable frames and
+  // |received_end_of_stream_| is true.  Sets |rendered_end_of_stream_| if it
+  // does so.  Returns algorithm_->EffectiveFramesQueued().
+  size_t MaybeFireEndedCallback();
+
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
+  // Enables the use of VideoRendererAlgorithm and VideoRendererSink for frame
+  // rendering instead of using a thread in a sleep-loop.  Set via the command
+  // line flag kEnableNewVideoRenderer or via test methods.
+  bool use_new_video_renderering_path_;
+
+  // Sink which calls into VideoRendererImpl via Render() for video frames.  Do
+  // not call any methods on the sink while |lock_| is held or the two threads
+  // might deadlock. Do not call Start() or Stop() on the sink directly, use
+  // StartSink() and StopSink() to ensure background rendering is started.
   VideoRendererSink* const sink_;
 
   // Used for accessing data members.
@@ -219,6 +261,32 @@ class MEDIA_EXPORT VideoRendererImpl
 
   scoped_ptr<base::TickClock> tick_clock_;
 
+  // Algorithm for selecting which frame to render; manages frames and all
+  // timing related information.
+  scoped_ptr<VideoRendererAlgorithm> algorithm_;
+
+  // Indicates that Render() callbacks from |sink_| have timed out, so we've
+  // entered a background rendering mode where dropped frames are not counted.
+  bool is_background_rendering_;
+
+  // Allows tests to disable the background rendering task.
+  bool should_use_background_renderering_;
+
+  // Manages expiration of stale video frames if Render() callbacks timeout.  Do
+  // not access from the thread Render() is called on.  Must only be used on
+  // |task_runner_|.
+  base::OneShotTimer<VideoRendererImpl> background_rendering_timer_;
+
+  // Indicates whether or not media time is currently progressing or not.
+  bool time_progressing_;
+
+  // Indicates that Render() should only render the first frame and then request
+  // that the sink be stopped.
+  bool render_first_frame_and_stop_;
+
+  // The time to wait for Render() before firing BackgroundRender().
+  base::TimeDelta background_rendering_timeout_;
+
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<VideoRendererImpl> weak_factory_;