Transfer media::VideoFrame using mojo shared memory

media/mojo/common/mojo_shared_buffer_video_frame.h

Index: media/mojo/common/mojo_shared_buffer_video_frame.h
diff --git a/media/mojo/common/mojo_shared_buffer_video_frame.h b/media/mojo/common/mojo_shared_buffer_video_frame.h
index 9d470fd3a9102dd9323a20fe1673b67f68f996aa..4720d1d0b3539597c204b2853e8395f57cf20de9 100644
--- a/media/mojo/common/mojo_shared_buffer_video_frame.h
+++ b/media/mojo/common/mojo_shared_buffer_video_frame.h
@@ -10,14 +10,26 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
 #include "media/base/video_frame.h"
 #include "mojo/public/cpp/system/buffer.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 
+namespace mojo {
+template <typename T, typename U>
+struct TypeConverter;
+template <typename T>
+class StructPtr;
+};
+
 namespace media {
 
+namespace interfaces {
+class VideoFrame;
+}
+
 // A derived class of media::VideoFrame holding a mojo::SharedBufferHandle
 // which is mapped on constructor and remains so for the lifetime of the
 // object. These frames are ref-counted.
@@ -54,6 +66,11 @@ class MEDIA_EXPORT MojoSharedBufferVideoFrame : public VideoFrame {
   size_t PlaneOffset(size_t plane) const;
 
  private:
+  // mojo::TypeConverter added as a friend so that MojoSharedBufferVideoFrame
+  // can be transferred across a mojo connection.
+  friend struct mojo::TypeConverter<mojo::StructPtr<interfaces::VideoFrame>,
+                                    scoped_refptr<VideoFrame>>;
+
   MojoSharedBufferVideoFrame(VideoPixelFormat format,
                              const gfx::Size& coded_size,
                              const gfx::Rect& visible_rect,
@@ -72,6 +89,14 @@ class MEDIA_EXPORT MojoSharedBufferVideoFrame : public VideoFrame {
             size_t u_offset,
             size_t v_offset);
 
+  // Returns the mojo shared memory handle. This object continues to own the
+  // handle. Caller should call duplicate the handle if they want to keep a
+  // copy of the shared memory.
+  const mojo::SharedBufferHandle& Handle() const;
+
+  // Returns the size of the shared memory.
+  size_t MappedSize() const;
+
   mojo::ScopedSharedBufferHandle shared_buffer_handle_;
   size_t shared_buffer_size_;
   uint8_t* shared_buffer_data_;