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..6523fe443519c709c23058054bf5b51729930240
--- /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 COMPONENT_ARC_VIDEO_ACCELERATOR_VIDEO_ACCELERATOR_H_
+#define COMPONENT_ARC_VIDEO_ACCELERATOR_VIDEO_ACCELERATOR_H_
+
+namespace arc {
+
+struct ArcVideoAcceleratorDmabufPlane {
+  int32_t offset;  // in bytes

[dcheng, 2016/12/01 01:30:50]

Perhaps note in a comment why these are signed despite the fact they should only
hold non-negative numbers.

(IIRC, it's related to off_t being involved, but I don't remember the details
anymore)

[yoshiki, 2016/12/02 08:31:43]

Powel, could you answer this question?

[Pawel Osciak, 2016/12/06 07:08:38]

They are signed because client APIs use ints for these.

[yoshiki, 2016/12/06 16:48:33]

Ok. Let me keep as-is.

+  int32_t stride;  // in bytes
+};
+
+}  // namespace arc
+
+#endif  // COMPONENT_ARC_VIDEO_ACCELERATOR_VIDEO_ACCELERATOR_H_