cc: Video layers without a frame should not occlude

media/blink/video_frame_compositor.h

 // 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.
 
 #ifndef MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_
 #define MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 60 matching lines @@
   // Destruction must happen on the compositor thread; Stop() must have been
   // called before destruction starts.
   ~VideoFrameCompositor() override;
 
   // cc::VideoFrameProvider implementation. These methods must be called on the
   // |compositor_task_runner_|.
   void SetVideoFrameProviderClient(
       cc::VideoFrameProvider::Client* client) override;
   bool UpdateCurrentFrame(base::TimeTicks deadline_min,
                           base::TimeTicks deadline_max) override;
+  bool HasCurrentFrame() override;
   scoped_refptr<VideoFrame> GetCurrentFrame() override;
   void PutCurrentFrame() override;
 
   // VideoRendererSink implementation. These methods must be called from the
   // same thread (typically the media thread).
   void Start(RenderCallback* callback) override;
   void Stop() override;
   void PaintFrameUsingOldRenderingPath(
       const scoped_refptr<VideoFrame>& frame) override;
 
@@ skipping 73 matching lines @@
   // These values are updated and read from the media and compositor threads.
   base::Lock lock_;
   VideoRendererSink::RenderCallback* callback_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoFrameCompositor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_