Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/base/video_decoder.h

Index: media/base/video_decoder.h
diff --git a/media/base/video_decoder.h b/media/base/video_decoder.h
index 226b7b2f01f6e4ac4e2f9fd5a6e35b00476f37f5..7dfc9bd6176069bafbb40667a9f8d31118698cd8 100644
--- a/media/base/video_decoder.h
+++ b/media/base/video_decoder.h
@@ -25,11 +25,16 @@ class MEDIA_EXPORT VideoDecoder {
   enum Status {
     kOk,  // Everything went as planned.
     kAborted,  // Decode was aborted as a result of Reset() being called.
-    kNotEnoughData,  // Not enough data to produce a video frame.
     kDecodeError,  // Decoding error happened.
     kDecryptError  // Decrypting error happened.
   };
 
+  // Callback to return decode frames.
+  typedef base::Callback<void(const scoped_refptr<VideoFrame>&)> OutputCB;
+
+  // Callback type for Decode().
+  typedef base::Callback<void(Status status)> DecodeCB;
+
   VideoDecoder();
   virtual ~VideoDecoder();
 
@@ -44,7 +49,8 @@ class MEDIA_EXPORT VideoDecoder {
   //    |status_cb| is executed.
   virtual void Initialize(const VideoDecoderConfig& config,
                           bool low_delay,
-                          const PipelineStatusCB& status_cb) = 0;
+                          const PipelineStatusCB& status_cb,
+                          const OutputCB& output_cb) = 0;
 
   // Requests a |buffer| to be decoded. The status of the decoder and decoded
   // frame are returned via the provided callback. Some decoders may allow
@@ -62,18 +68,9 @@ class MEDIA_EXPORT VideoDecoder {
   // - Non-EOS (end of stream) frame contains decoded video data.
   // - EOS frame indicates the end of the stream.
   // Otherwise the returned frame must be NULL.

[xhwang, 2014/05/29 22:15:14]

This whole comment block needs to be updated.

[Sergey Ulanov, 2014/06/03 00:08:11]

Done.

-  typedef base::Callback<void(Status,
-                              const scoped_refptr<VideoFrame>&)> DecodeCB;
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const DecodeCB& decode_cb) = 0;
 
-  // Some VideoDecoders may queue up multiple VideoFrames from a single
-  // DecoderBuffer, if we have any such queued frames this will return the next
-  // one. Otherwise we return a NULL VideoFrame.
-  //
-  // TODO(xhwang): Revisit this method.
-  virtual scoped_refptr<VideoFrame> GetDecodeOutput();
-
   // Resets decoder state, fulfilling all pending DecodeCB and dropping extra
   // queued decoded data. After this call, the decoder is back to an initialized
   // clean state.