[Mojo Video Capture] Decouple VCController from VCBufferPool and VCDeviceClient

content/browser/renderer_host/media/video_frame_receiver_on_io_thread.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 CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_FRAME_RECEIVER_ON_IO_THREAD_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_FRAME_RECEIVER_ON_IO_THREAD_H_
+
+#include "content/common/content_export.h"
+#include "media/capture/video/video_frame_receiver.h"
+
+namespace content {
+
+// Decorator for media::VideoFrameReceiver that forwards all incoming calls
+// to the Browser IO thread.
+class CONTENT_EXPORT VideoFrameReceiverOnIOThread
+    : public media::VideoFrameReceiver {
+ public:
+  explicit VideoFrameReceiverOnIOThread(
+      const base::WeakPtr<VideoFrameReceiver>& receiver);
+  ~VideoFrameReceiverOnIOThread() override;
+
+  void OnIncomingCapturedVideoFrame(
+      std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
+      scoped_refptr<media::VideoFrame> frame) override;
+  void OnError() override;
+  void OnLog(const std::string& message) override;
+  void OnBufferDestroyed(int buffer_id_to_drop) override;
+
+ private:
+  base::WeakPtr<VideoFrameReceiver> receiver_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_FRAME_RECEIVER_ON_IO_THREAD_H_