Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/filters/vpx_video_decoder.h

Index: media/filters/vpx_video_decoder.h
diff --git a/media/filters/vpx_video_decoder.h b/media/filters/vpx_video_decoder.h
index 9fd004236e56d200dad325d94d260c067d6f8a2f..22d119bea7e682fd178774a58b974ae49ba8b591 100644
--- a/media/filters/vpx_video_decoder.h
+++ b/media/filters/vpx_video_decoder.h
@@ -34,7 +34,8 @@ class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
   // VideoDecoder implementation.
   virtual void Initialize(const VideoDecoderConfig& config,
                           bool low_delay,
-                          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 void Reset(const base::Closure& closure) OVERRIDE;
@@ -67,6 +68,8 @@ class MEDIA_EXPORT VpxVideoDecoder : public VideoDecoder {
 
   DecoderState state_;
 
+  OutputCB output_cb_;
+
   // TODO(xhwang): Merge DecodeBuffer() into Decode() and remove this.
   DecodeCB decode_cb_;