Add mailbox-based Mojo VideoFrame variant.

media/mojo/clients/mojo_video_decoder.h

Index: media/mojo/clients/mojo_video_decoder.h
diff --git a/media/mojo/clients/mojo_video_decoder.h b/media/mojo/clients/mojo_video_decoder.h
index bb13271206bedef4e8e009d72848cdd327a994eb..56f0b66d0047af2beb03b3927fef3b510d7333c3 100644
--- a/media/mojo/clients/mojo_video_decoder.h
+++ b/media/mojo/clients/mojo_video_decoder.h
@@ -47,7 +47,8 @@ class MojoVideoDecoder final : public VideoDecoder,
   int GetMaxDecodeRequests() const final;
 
   // mojom::VideoDecoderClient implementation.
-  void OnVideoFrameDecoded(mojom::VideoFramePtr frame) final;
+  void OnVideoFrameDecoded(mojom::VideoFramePtr frame,
+                           const OnVideoFrameDecodedCallback& callback) final;
 
  private:
   void OnInitializeDone(bool status,
@@ -57,6 +58,8 @@ class MojoVideoDecoder final : public VideoDecoder,
   void OnResetDone();
 
   void BindRemoteDecoder();
+  void OnReleaseMailbox(const OnVideoFrameDecodedCallback& callback,
+                        const gpu::SyncToken& release_sync_token);
 
   // Cleans up callbacks and blocks future calls.
   void Stop();