Break tight coupling of VideoCaptureDeviceClient to renderer_host

content/browser/renderer_host/media/video_capture_controller.h

Index: content/browser/renderer_host/media/video_capture_controller.h
diff --git a/content/browser/renderer_host/media/video_capture_controller.h b/content/browser/renderer_host/media/video_capture_controller.h
index a9b93206405f5d4a777ecdb0687bf18e9226a912..c71fc9427af4c9af1e9024144620e86bc1f352d6 100644
--- a/content/browser/renderer_host/media/video_capture_controller.h
+++ b/content/browser/renderer_host/media/video_capture_controller.h
@@ -57,7 +57,19 @@
 namespace content {
 class VideoCaptureBufferPool;
 
-class CONTENT_EXPORT VideoCaptureController {
+class CONTENT_EXPORT VideoFrameReceiver {
+ public:
+  virtual ~VideoFrameReceiver(){};
+
+  virtual void OnIncomingCapturedVideoFrame(
+      std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
+      const scoped_refptr<media::VideoFrame>& frame) = 0;
+  virtual void OnError() = 0;
+  virtual void OnLog(const std::string& message) = 0;
+  virtual void OnBufferDestroyed(int buffer_id_to_drop) = 0;
+};
+
+class CONTENT_EXPORT VideoCaptureController : public VideoFrameReceiver {
  public:
   // |max_buffers| is the maximum number of video frame buffers in-flight at any
   // one time.  This value should be based on the logical capacity of the
@@ -65,7 +77,7 @@ class CONTENT_EXPORT VideoCaptureController {
   // capture requires more buffers than webcam capture because the pipeline is
   // longer (it includes read-backs pending in the GPU pipeline).
   explicit VideoCaptureController(int max_buffers);
-  virtual ~VideoCaptureController();
+  ~VideoCaptureController() override;
 
   base::WeakPtr<VideoCaptureController> GetWeakPtrForIOThread();
 
@@ -125,13 +137,13 @@ class CONTENT_EXPORT VideoCaptureController {
 
   bool has_received_frames() const { return has_received_frames_; }
 
-  // Worker functions on IO thread. Called by the VideoCaptureDeviceClient.
-  virtual void DoIncomingCapturedVideoFrameOnIOThread(
+  // Implementation of VideoFrameReceiver interface:
+  void OnIncomingCapturedVideoFrame(
       std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
-      const scoped_refptr<media::VideoFrame>& frame);
-  virtual void DoErrorOnIOThread();
-  virtual void DoLogOnIOThread(const std::string& message);
-  virtual void DoBufferDestroyedOnIOThread(int buffer_id_to_drop);
+      const 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:
   struct ControllerClient;