Make FFmpegVideoDecoder defer a flush until the pending read completes.

media/filters/ffmpeg_video_decoder.h

 // Copyright (c) 2012 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_FILTERS_FFMPEG_VIDEO_DECODER_H_
 #define MEDIA_FILTERS_FFMPEG_VIDEO_DECODER_H_
 
 #include <deque>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 46 matching lines @@
   bool Decode(const scoped_refptr<Buffer>& buffer,
               scoped_refptr<VideoFrame>* video_frame);
 
   // Delivers the frame to |read_cb_| and resets the callback.
   void DeliverFrame(const scoped_refptr<VideoFrame>& video_frame);
 
   // Releases resources associated with |codec_context_| and |av_frame_|
   // and resets them to NULL.
   void ReleaseFFmpegResources();
 
+  // Flush decoder and call |flush_cb_|.
+  void DoFlush();
+
   // Allocates a video frame based on the current format and dimensions based on
   // the current state of |codec_context_|.
   scoped_refptr<VideoFrame> AllocateVideoFrame();
 
   MessageLoop* message_loop_;
 
   DecoderState state_;
 
   StatisticsCB statistics_cb_;
 
   ReadCB read_cb_;
+  base::Closure flush_cb_;
 
   // FFmpeg structures owned by this object.
   AVCodecContext* codec_context_;
   AVFrame* av_frame_;
 
   // Frame rate of the video.
   int frame_rate_numerator_;
   int frame_rate_denominator_;
 
   // TODO(scherkus): I think this should be calculated by VideoRenderers based
   // on information provided by VideoDecoders (i.e., aspect ratio).
   gfx::Size natural_size_;
 
   // Pointer to the demuxer stream that will feed us compressed buffers.
   scoped_refptr<DemuxerStream> demuxer_stream_;
 
   AesDecryptor decryptor_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegVideoDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_VIDEO_DECODER_H_