Use mojo typemap to simplify the code using DmabufPlane

components/arc/video_accelerator/video_accelerator.h

Index: components/arc/video_accelerator/video_accelerator.h
diff --git a/components/arc/video_accelerator/video_accelerator.h b/components/arc/video_accelerator/video_accelerator.h
new file mode 100644
index 0000000000000000000000000000000000000000..bdbf6d5466f134c1eebb101fcd25b06644510aec
--- /dev/null
+++ b/components/arc/video_accelerator/video_accelerator.h
@@ -0,0 +1,17 @@
+// Copyright 2016 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 COMPONENTS_ARC_VIDEO_ACCELERATOR_VIDEO_ACCELERATOR_H_
+#define COMPONENTS_ARC_VIDEO_ACCELERATOR_VIDEO_ACCELERATOR_H_
+
+namespace arc {
+
+struct ArcVideoAcceleratorDmabufPlane {
+  int32_t offset;  // in bytes
+  int32_t stride;  // in bytes
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_ARC_VIDEO_ACCELERATOR_VIDEO_ACCELERATOR_H_