Enable fire-and-forget Destroy of HW video decoder, and misc other improvements.

content/renderer/pepper_platform_video_decoder_impl.h

 // Copyright (c) 2011 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 CONTENT_RENDERER_PEPPER_PLATFORM_VIDEO_DECODER_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PLATFORM_VIDEO_DECODER_IMPL_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "media/video/video_decode_accelerator.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 
 class GpuChannelHost;
 namespace gpu {
 class CommandBufferHelper;
 }
 
 class PlatformVideoDecoderImpl
     : public webkit::ppapi::PluginDelegate::PlatformVideoDecoder,
       public media::VideoDecodeAccelerator::Client {
  public:
   PlatformVideoDecoderImpl(
       media::VideoDecodeAccelerator::Client* client,
       int32 command_buffer_route_id,
       gpu::CommandBufferHelper* cmd_buffer_helper);
-  virtual ~PlatformVideoDecoderImpl();
 
-  // PlatformVideoDecoder implementation.
+  // PlatformVideoDecoder (a.k.a. VideoDecodeAccelerator) implementation.
   virtual bool Initialize(const std::vector<uint32>& configs) OVERRIDE;
   virtual void Decode(
       const media::BitstreamBuffer& bitstream_buffer) OVERRIDE;
   virtual void AssignGLESBuffers(
       const std::vector<media::GLESBuffer>& buffers) OVERRIDE;
   virtual void ReusePictureBuffer(int32 picture_buffer_id);
   virtual void Flush() OVERRIDE;
   virtual void Reset() OVERRIDE;
   virtual void Destroy() OVERRIDE;
 
   // VideoDecodeAccelerator::Client implementation.
   virtual void ProvidePictureBuffers(
       uint32 requested_num_of_buffers,
       const gfx::Size& dimensions,
       media::VideoDecodeAccelerator::MemoryType type) OVERRIDE;
   virtual void PictureReady(const media::Picture& picture) OVERRIDE;
   virtual void DismissPictureBuffer(int32 picture_buffer_id) OVERRIDE;
   virtual void NotifyInitializeDone() OVERRIDE;
   virtual void NotifyEndOfStream() OVERRIDE;
   virtual void NotifyError(
       media::VideoDecodeAccelerator::Error error) OVERRIDE;
   virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) OVERRIDE;
   virtual void NotifyFlushDone() OVERRIDE;
   virtual void NotifyResetDone() OVERRIDE;
-  virtual void NotifyDestroyDone() OVERRIDE;
 
  private:
+  virtual ~PlatformVideoDecoderImpl();
+
   // Client lifetime must exceed lifetime of this class.
   // TODO(vrk/fischman): We should take another look at the overall
   // arcitecture of PPAPI Video Decode to make sure lifetime/ownership makes
   // sense, including lifetime of this client.
   media::VideoDecodeAccelerator::Client* client_;
 
   // Route ID for the command buffer associated with video decoder's context.
   int32 command_buffer_route_id_;
 
   // Helper for the command buffer associated with video decoder's context.
   gpu::CommandBufferHelper* cmd_buffer_helper_;
 
-  // Host for GpuVideoDecodeAccelerator.
-  // This is owned by the CommandBufferProxy associated with
-  // |command_buffer_route_id|.
-  media::VideoDecodeAccelerator* decoder_;
+  // Holds a GpuVideoDecodeAcceleratorHost.
+  scoped_refptr<media::VideoDecodeAccelerator> decoder_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformVideoDecoderImpl);
 };
 #endif  // CONTENT_RENDERER_PEPPER_PLATFORM_VIDEO_DECODER_IMPL_H_