Support multiple video decoders and encoders

content/common/gpu/media/gpu_video_decode_accelerator.h

Index: content/common/gpu/media/gpu_video_decode_accelerator.h
diff --git a/content/common/gpu/media/gpu_video_decode_accelerator.h b/content/common/gpu/media/gpu_video_decode_accelerator.h
index e59a76fb5c35169dd4b0fab8cb448e9bc02a46b3..2c93becd56150e820c85ca9f85cfdb7c1a95286b 100644
--- a/content/common/gpu/media/gpu_video_decode_accelerator.h
+++ b/content/common/gpu/media/gpu_video_decode_accelerator.h
@@ -59,14 +59,29 @@ class GpuVideoDecodeAccelerator
   // Function to delegate sending to actual sender.
   bool Send(IPC::Message* message) override;
 
-  // Initialize the accelerator with the given profile and send the
-  // |init_done_msg| when done.
+  // Initialize VDAs from the set of VDAs supported for current platform until
+  // one of them succeeds for given |profile|. Send the |init_done_msg| when
+  // done. filter_ is passed to GpuCommandBufferStub channel only if the chosen
+  // VDA can decode on IO thread.
   void Initialize(const media::VideoCodecProfile profile,
                   IPC::Message* init_done_msg);
 
  private:
+  typedef base::Callback<scoped_ptr<media::VideoDecodeAccelerator>(void)>
+      CreateVDACb;
+
   class MessageFilter;
 
+  // Return a set of VDA Create callback functions applicable to the current
+  // platform.
+  std::vector<CreateVDACb> CreateVDACbs();
+  scoped_ptr<media::VideoDecodeAccelerator> CreateDXVAVDA();
+  scoped_ptr<media::VideoDecodeAccelerator> CreateV4L2VDA();
+  scoped_ptr<media::VideoDecodeAccelerator> CreateVaapiVDA();
+  scoped_ptr<media::VideoDecodeAccelerator> CreateVTVDA();
+  scoped_ptr<media::VideoDecodeAccelerator> CreateOzoneVDA();
+  scoped_ptr<media::VideoDecodeAccelerator> CreateAndroidVDA();
+
   // We only allow self-delete, from OnWillDestroyStub(), after cleanup there.
   ~GpuVideoDecodeAccelerator() override;