Simplify VideoDecodeEngine interface by making everything synchronous.

content/renderer/media/capture_video_decoder.h

 // Copyright (c) 2011 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_CAPTURE_VIDEO_DECODER_H_
 #define CONTENT_RENDERER_MEDIA_CAPTURE_VIDEO_DECODER_H_
 
 #include <deque>
 
 #include "base/time.h"
@@ skipping 26 matching lines @@
   virtual void Seek(base::TimeDelta time,
                     const media::FilterStatusCB& cb) OVERRIDE;
   virtual void Pause(const base::Closure& callback) OVERRIDE;
   virtual void Stop(const base::Closure& callback) OVERRIDE;
 
   // Decoder implementation.
   virtual void Initialize(
       media::DemuxerStream* demuxer_stream,
       const base::Closure& filter_callback,
       const media::StatisticsCallback& stat_callback) OVERRIDE;
-  virtual void ProduceVideoFrame(
-      scoped_refptr<media::VideoFrame> video_frame) OVERRIDE;
-  virtual gfx::Size natural_size() OVERRIDE;
+  virtual void Read(const ReadCB& callback) OVERRIDE;
+  virtual const gfx::Size& natural_size() OVERRIDE;
 
   // VideoCapture::EventHandler implementation.
   virtual void OnStarted(media::VideoCapture* capture) OVERRIDE;
   virtual void OnStopped(media::VideoCapture* capture) OVERRIDE;
   virtual void OnPaused(media::VideoCapture* capture) OVERRIDE;
   virtual void OnError(media::VideoCapture* capture, int error_code) OVERRIDE;
   virtual void OnRemoved(media::VideoCapture* capture) OVERRIDE;
   virtual void OnBufferReady(
       media::VideoCapture* capture,
       scoped_refptr<media::VideoCapture::VideoFrameBuffer> buf) OVERRIDE;
   virtual void OnDeviceInfoReceived(
       media::VideoCapture* capture,
       const media::VideoCaptureParams& device_info) OVERRIDE;
 
  private:
   friend class CaptureVideoDecoderTest;
 
   enum DecoderState {
     kUnInitialized,
     kNormal,
-    kSeeking,
     kStopped,
     kPaused
   };
 
   void PlayOnDecoderThread(const base::Closure& callback);
   void SeekOnDecoderThread(base::TimeDelta time,
                            const media::FilterStatusCB& cb);
   void PauseOnDecoderThread(const base::Closure& callback);
   void StopOnDecoderThread(const base::Closure& callback);
 
   void InitializeOnDecoderThread(
       media::DemuxerStream* demuxer_stream,
       const base::Closure& filter_callback,
       const media::StatisticsCallback& stat_callback);
-  void ProduceVideoFrameOnDecoderThread(
-      scoped_refptr<media::VideoFrame> video_frame);
+  void ReadOnDecoderThread(const ReadCB& callback);
 
   void OnStoppedOnDecoderThread(media::VideoCapture* capture);
   void OnBufferReadyOnDecoderThread(
       media::VideoCapture* capture,
       scoped_refptr<media::VideoCapture::VideoFrameBuffer> buf);
 
+  // Delivers the frame to |read_cb_| and resets the callback.
+  void DeliverFrame(const scoped_refptr<media::VideoFrame>& video_frame);
+
   scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
   scoped_refptr<VideoCaptureImplManager> vc_manager_;
   media::VideoCapture::VideoCaptureCapability capability_;
+  gfx::Size natural_size_;
   DecoderState state_;
-  std::deque<scoped_refptr<media::VideoFrame> > available_frames_;
+  ReadCB read_cb_;
   base::Closure pending_stop_cb_;
   media::StatisticsCallback statistics_callback_;
 
   media::VideoCaptureSessionId video_stream_id_;
   media::VideoCapture* capture_engine_;
   base::Time start_time_;
 
   DISALLOW_COPY_AND_ASSIGN(CaptureVideoDecoder);
 };
 
 #endif  // CONTENT_RENDERER_MEDIA_CAPTURE_VIDEO_DECODER_H_