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

content/common/gpu/media/v4l2_slice_video_decode_accelerator.h

Index: content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
diff --git a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
index 87fe1967d1fa19cf5cc8e82a2c0dfecd13ffc0a6..5098349878204448690f4f851f823276950d0145 100644
--- a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
+++ b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
@@ -50,7 +50,7 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   void AssignPictureBuffers(
       const std::vector<media::PictureBuffer>& buffers) override;
   void ReusePictureBuffer(int32_t picture_buffer_id) override;
-  void Flush() override;
+  void Flush(bool return_buffers) override;
   void Reset() override;
   void Destroy() override;
   bool CanDecodeOnIOThread() override;
@@ -183,7 +183,7 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   // InitiateFlush() directly. Otherwise, we push a dummy BitstreamBufferRef
   // onto the decoder_input_queue_ to schedule a flush. When we reach it later
   // on, we call InitiateFlush() to perform it at the correct time.
-  void FlushTask();
+  void FlushTask(bool return_buffers);
   // Tell the decoder to flush all frames, reset it and mark us as scheduled
   // for flush, so that we can finish it once all pending decodes are finished.
   void InitiateFlush();
@@ -372,6 +372,10 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   bool decoder_resetting_;
   bool surface_set_change_pending_;
 
+  // When flushing, if true, indicates that we were requested to return all
+  // output buffers, not only those containing pictures produced during flush.
+  bool flush_return_all_buffers_;
+
   // Hardware accelerators.
   // TODO(posciak): Try to have a superclass here if possible.
   scoped_ptr<V4L2H264Accelerator> h264_accelerator_;