Add an additional VDA::Flush() mode to return all allocated buffers.

media/video/video_decode_accelerator.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_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
 #define MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 189 matching lines @@
   // Sends picture buffers to be reused by the decoder. This needs to be called
   // for each buffer that has been processed so that decoder may know onto which
   // picture buffers it can write the output to.
   //
   // Parameters:
   //  |picture_buffer_id| id of the picture buffer that is to be reused.
   virtual void ReusePictureBuffer(int32_t picture_buffer_id) = 0;
 
   // Flushes the decoder: all pending inputs will be decoded and pictures handed
   // back to the client, followed by NotifyFlushDone() being called on the
-  // client.  Can be used to implement "end of stream" notification.
-  virtual void Flush() = 0;
+  // client. If |return_buffers| is true, VDA must return all PictureBuffers it

[kcwu, 2016/03/22 09:47:42]

s/return all PictureBuffers/return all PictureBuffers via PictureReady/

+  // owns, not only ones containing pictures remaining in the decoder at the
+  // time of this call. To indicate a returned buffer does not contain a decoded
+  // frame, the VDA must set bitstream_buffer_id = -1 in the returned Picture.
+  // Can be used to implement "end of stream" notification.
+  virtual void Flush(bool return_buffers) = 0;

[kcwu, 2016/03/22 09:47:42]

How about move the description of |return_buffers| to after 'Can be used to
implement "end of stream" notification.' or into separate "Parameters:" section?
Otherwise I was confused that 'Can be used to implement "end of stream"
notification.' is related to |return_buffers|.

 
   // Resets the decoder: all pending inputs are dropped immediately and the
   // decoder returned to a state ready for further Decode()s, followed by
   // NotifyResetDone() being called on the client.  Can be used to implement
   // "seek".
   virtual void Reset() = 0;
 
   // Destroys the decoder: all pending inputs are dropped immediately and the
   // component is freed.  This call may asynchornously free system resources,
   // but its client-visible effects are synchronous.  After this method returns
@@ skipping 29 matching lines @@
 // Specialize std::default_delete so that scoped_ptr<VideoDecodeAccelerator>
 // uses "Destroy()" instead of trying to use the destructor.
 template <>
 struct MEDIA_EXPORT default_delete<media::VideoDecodeAccelerator> {
   void operator()(media::VideoDecodeAccelerator* vda) const;
 };
 
 }  // namespace std
 
 #endif  // MEDIA_VIDEO_VIDEO_DECODE_ACCELERATOR_H_