Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/filters/ffmpeg_audio_decoder.h

Index: media/filters/ffmpeg_audio_decoder.h
diff --git a/media/filters/ffmpeg_audio_decoder.h b/media/filters/ffmpeg_audio_decoder.h
index 89360220f3689122f4458e4bf0447a009d59cf10..86a81d966d4d162aef09e12b7dbfde89bcb43ed9 100644
--- a/media/filters/ffmpeg_audio_decoder.h
+++ b/media/filters/ffmpeg_audio_decoder.h
@@ -37,10 +37,10 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
 
   // AudioDecoder implementation.
   virtual void Initialize(const AudioDecoderConfig& config,
-                          const PipelineStatusCB& status_cb) OVERRIDE;
+                          const PipelineStatusCB& status_cb,
+                          const OutputCB& output_cb) OVERRIDE;
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const DecodeCB& decode_cb) OVERRIDE;
-  virtual scoped_refptr<AudioBuffer> GetDecodeOutput() OVERRIDE;
   virtual void Reset(const base::Closure& closure) OVERRIDE;
   virtual void Stop() OVERRIDE;
 
@@ -72,6 +72,8 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
+  OutputCB output_cb_;
+
   DecoderState state_;
 
   // FFmpeg structures owned by this object.
@@ -85,10 +87,6 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
 
   scoped_ptr<AudioDiscardHelper> discard_helper_;
 
-  // Since multiple frames may be decoded from the same packet we need to queue
-  // them up.
-  std::list<scoped_refptr<AudioBuffer> > queued_audio_;
-
   LogCB log_cb_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(FFmpegAudioDecoder);