Support external buffer import in VDA interface and add a V4L2SVDA impl.

content/common/gpu/media/v4l2_video_decode_accelerator.h

 // Copyright 2014 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.
 //
 // This file contains an implementation of VideoDecodeAccelerator
 // that utilizes hardware video decoders, which expose Video4Linux 2 API
 // (http://linuxtv.org/downloads/v4l-dvb-apis/).
 
 #ifndef CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_DECODE_ACCELERATOR_H_
 #define CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_DECODE_ACCELERATOR_H_
@@ skipping 80 matching lines @@
   void AssignPictureBuffers(
       const std::vector<media::PictureBuffer>& buffers) override;
   void ReusePictureBuffer(int32_t picture_buffer_id) override;
   void Flush() override;
   void Reset() override;
   void Destroy() override;
   bool TryToSetupDecodeOnSeparateThread(
       const base::WeakPtr<Client>& decode_client,
       const scoped_refptr<base::SingleThreadTaskRunner>& decode_task_runner)
       override;
+  media::VideoPixelFormat GetOutputFormat() const override;
 
   static media::VideoDecodeAccelerator::SupportedProfiles
       GetSupportedProfiles();
 
  private:
   // These are rather subjectively tuned.
   enum {
     kInputBufferCount = 8,
     // TODO(posciak): determine input buffer size based on level limits.
     // See http://crbug.com/255116.
@@ skipping 347 matching lines @@
 
   // The WeakPtrFactory for |weak_this_|.
   base::WeakPtrFactory<V4L2VideoDecodeAccelerator> weak_this_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(V4L2VideoDecodeAccelerator);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_DECODE_ACCELERATOR_H_