Avoid creating sync token when only change is new hardware video frame.

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 <stddef.h>
 #include <stdint.h>
 
 #include <list>
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "gpu/command_buffer/common/sync_token.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/surface_manager.h"
 #include "media/base/video_decoder.h"
 #include "media/video/video_decode_accelerator.h"
 
 template <class T> class scoped_refptr;
 
 namespace base {
 class SharedMemory;
 class SingleThreadTaskRunner;
@@ skipping 150 matching lines @@
 
   State state_;
 
   VideoDecoderConfig config_;
 
   // Shared-memory buffer pool.  Since allocating SHM segments requires a
   // round-trip to the browser process, we keep allocation out of the
   // steady-state of the decoder.
   std::vector<SHMBuffer*> available_shm_segments_;
 
+  // Placeholder sync token that was created and validated after the most
+  // recent picture buffers were created.
+  gpu::SyncToken sync_token_;
+
   std::map<int32_t, PendingDecoderBuffer> bitstream_buffers_in_decoder_;
   PictureBufferMap assigned_picture_buffers_;
   // PictureBuffers given to us by VDA via PictureReady, which we sent forward
   // as VideoFrames to be rendered via decode_cb_, and which will be returned
   // to us via ReusePictureBuffer.
   typedef std::map<int32_t /* picture_buffer_id */,
                    PictureBuffer::TextureIds /* texture_id */>
       PictureBufferTextureMap;
   PictureBufferTextureMap picture_buffers_at_display_;
 
@@ skipping 42 matching lines @@
   // 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_