Don't require VDAs to return all PictureBuffers at once.

media/filters/gpu_video_decoder.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_FILTERS_GPU_VIDEO_DECODER_H_
 #define MEDIA_FILTERS_GPU_VIDEO_DECODER_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 118 matching lines @@
   // allocate as necessary.
   scoped_ptr<SHMBuffer> GetSHM(size_t min_size);
 
   // Return a shared-memory segment to the available pool.
   void PutSHM(scoped_ptr<SHMBuffer> shm_buffer);
 
   // Destroy all PictureBuffers in |buffers|, and delete their textures.
   void DestroyPictureBuffers(PictureBufferMap* buffers);
 
   // Returns true if the video decoder can support |profile| and |coded_size|.
-  bool IsProfileSupported(VideoCodecProfile profile,
-                          const gfx::Size& coded_size);
+  // On success, |matching_profile_out| contains a copy of the matching
+  // profile.  On failure, it is undefined.
+  bool IsProfileSupported(
+      VideoCodecProfile profile,
+      const gfx::Size& coded_size,
+      VideoDecodeAccelerator::SupportedProfile& matching_profile_out);

[Pawel Osciak, 2015/12/04 11:09:45]

Non-const reference arguments are prohibited by coding style
(https://google.github.io/styleguide/cppguide.html#Reference_Arguments).

[liberato (no reviews please), 2015/12/04 18:28:58]

Done.

 
   // Assert the contract that this class is operated on the right thread.
   void DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent() const;
 
   bool needs_bitstream_conversion_;
 
   GpuVideoAcceleratorFactories* factories_;
 
   // Populated during Initialize() (on success) and unchanged until an error
   // occurs.
@@ skipping 45 matching lines @@
 
   // picture_buffer_id and the frame wrapping the corresponding Picture, for
   // frames that have been decoded but haven't been requested by a Decode() yet.
   int32 next_picture_buffer_id_;
   int32 next_bitstream_buffer_id_;
 
   // Set during ProvidePictureBuffers(), used for checking and implementing
   // HasAvailableOutputFrames().
   int available_pictures_;
 
+  // If false, then we may assume that the VDA cannot stall sending picture
+  // buffers until all of them have decoded frames.  If true, then it may
+  // stall as long as one picture buffer is outstanding.
+  bool can_stall_anytime_;
+
   // Bound to factories_->GetMessageLoop().
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<GpuVideoDecoder> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuVideoDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_GPU_VIDEO_DECODER_H_