Mojo Video Capture service in media/capture

media/capture/service/mojo_video_frame.h

+// 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 MEDIA_CAPTURE_SERVICE_MOJO_VIDEO_FRAME_H_
+#define MEDIA_CAPTURE_SERVICE_MOJO_VIDEO_FRAME_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/time/time.h"
+#include "media/base/video_frame.h"
+#include "mojo/public/cpp/system/buffer.h"
+
+namespace gfx {
+class Size;
+}
+
+namespace media {
+
+// A derived class of media::VideoFrame holding a mojo::SharedBuffer which is
+// mapped on constructor and remains so for the lifetime of the MojoVideoFrame.
+// The underlying VideoFrame uses this SharedBuffer as storage. MojoVideoFrames
+// frames are ref-counted, always I420, and coded_size() == natural_size() ==
+// visible_rect().
+class MojoVideoFrame : public media::VideoFrame {
+ public:
+  // Creates and maps a MojoVideoFrame or returns nullptr.
+  static scoped_refptr<MojoVideoFrame> CreateMojoVideoFrame(
+      const gfx::Size& dimensions,
+      base::TimeDelta timestamp);
+
+  mojo::SharedBufferHandle handle() { return shared_buffer_.handle.get(); }
+  size_t mapped_size() const { return shared_buffer_size_; }
+
+ private:
+  explicit MojoVideoFrame(const gfx::Size& dimensions,
+                          base::TimeDelta timestamp);
+  ~MojoVideoFrame() override;
+
+  // Maps |shared_buffer_| or returns false.
+  bool Init();
+
+  const size_t shared_buffer_size_;
+  const mojo::SharedBuffer shared_buffer_;
+};
+
+}  // namespace media
+
+#endif  // MEDIA_CAPTURE_SERVICE_MOJO_VIDEO_FRAME_H_