Break tight coupling of VideoCaptureDeviceClient to renderer_host

content/browser/renderer_host/media/video_capture_controller.h

 // Copyright (c) 2012 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.
 //
 // VideoCaptureController is the glue between a VideoCaptureDevice and all
 // VideoCaptureHosts that have connected to it. A controller exists on behalf of
 // one (and only one) VideoCaptureDevice; both are owned by the
 // VideoCaptureManager.
 //
 // The VideoCaptureController is responsible for:
@@ skipping 39 matching lines @@
 #include "base/process/process.h"
 #include "content/browser/renderer_host/media/video_capture_controller_event_handler.h"
 #include "content/common/content_export.h"
 #include "content/common/media/video_capture.h"
 #include "media/base/video_capture_types.h"
 #include "media/capture/video/video_capture_device.h"
 
 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
   // capture pipeline, and not on hardware performance.  For example, tab
   // 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();
 
   // Return a new VideoCaptureDeviceClient to forward capture events to this
   // instance.
   std::unique_ptr<media::VideoCaptureDevice::Client> NewDeviceClient();
 
   // Start video capturing and try to use the resolution specified in |params|.
   // Buffers will be shared to the client as necessary. The client will continue
   // to receive frames from the device until RemoveClient() is called.
@@ skipping 39 matching lines @@
   void ReturnBuffer(VideoCaptureControllerID id,
                     VideoCaptureControllerEventHandler* event_handler,
                     int buffer_id,
                     const gpu::SyncToken& sync_token,
                     double consumer_resource_utilization);
 
   const media::VideoCaptureFormat& GetVideoCaptureFormat() const;
 
   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;
   typedef std::list<std::unique_ptr<ControllerClient>> ControllerClients;
 
   // Notify renderer that a new buffer has been created.
   void DoNewBufferOnIOThread(ControllerClient* client,
                              media::VideoCaptureDevice::Client::Buffer* buffer,
                              const scoped_refptr<media::VideoFrame>& frame);
 
@@ skipping 22 matching lines @@
   media::VideoCaptureFormat video_capture_format_;
 
   base::WeakPtrFactory<VideoCaptureController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_CONTROLLER_H_