Allow VideoCaptureImpl to suspend/resume frame delivery to its client.

content/renderer/media/video_capture_impl.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.
 
 // VideoCaptureImpl represents a capture device in renderer process. It provides
 // interfaces for clients to Start/Stop capture. It also communicates to clients
 // when buffer is ready, state of capture device is changed.
 
 // VideoCaptureImpl is also a delegate of VideoCaptureMessageFilter which
 // relays operation of capture device to browser process and receives response
@@ skipping 39 matching lines @@
 
   // VideoCaptureMessageFilter::Delegate interface.
   virtual void OnBufferCreated(base::SharedMemoryHandle handle,
                                int length, int buffer_id) OVERRIDE;
   virtual void OnBufferReceived(int buffer_id, base::Time timestamp) OVERRIDE;
   virtual void OnStateChanged(VideoCaptureState state) OVERRIDE;
   virtual void OnDeviceInfoReceived(
       const media::VideoCaptureParams& device_info) OVERRIDE;
   virtual void OnDelegateAdded(int32 device_id) OVERRIDE;
 
+  // Stop/resume delivering video frames to clients, based on flag |suspend|.
+  virtual void SuspendCapture(bool suspend);
+
  private:
   friend class VideoCaptureImplManager;
   friend class VideoCaptureImplTest;
   friend class MockVideoCaptureImpl;
 
   struct DIBBuffer;
   typedef std::map<media::VideoCapture::EventHandler*,
       media::VideoCaptureCapability> ClientInfo;
 
   VideoCaptureImpl(media::VideoCaptureSessionId id,
                    base::MessageLoopProxy* capture_message_loop_proxy,
                    VideoCaptureMessageFilter* filter);
   virtual ~VideoCaptureImpl();
 
   void DoStartCaptureOnCaptureThread(
       media::VideoCapture::EventHandler* handler,
       const media::VideoCaptureCapability& capability);
   void DoStopCaptureOnCaptureThread(media::VideoCapture::EventHandler* handler);
   void DoFeedBufferOnCaptureThread(scoped_refptr<VideoFrameBuffer> buffer);
 
   void DoBufferCreatedOnCaptureThread(base::SharedMemoryHandle handle,
                                       int length, int buffer_id);
   void DoBufferReceivedOnCaptureThread(int buffer_id, base::Time timestamp);
   void DoStateChangedOnCaptureThread(VideoCaptureState state);
   void DoDeviceInfoReceivedOnCaptureThread(
       const media::VideoCaptureParams& device_info);
   void DoDelegateAddedOnCaptureThread(int32 device_id);
 
+  void DoSuspendCaptureOnCaptureThread(bool suspend);
+
   void Init();
   void DeInit(base::Closure task);
   void DoDeInitOnCaptureThread(base::Closure task);
   void StopDevice();
   void RestartCapture();
   void StartCaptureInternal();
   void AddDelegateOnIOThread();
   void RemoveDelegateOnIOThread(base::Closure task);
   virtual void Send(IPC::Message* message);
 
@@ skipping 19 matching lines @@
   media::VideoCaptureCapability::Format video_type_;
 
   // The parameter is being used in current capture session. A capture session
   // starts with StartCapture and ends with StopCapture.
   media::VideoCaptureParams current_params_;
 
   // The information about the device sent from browser process side.
   media::VideoCaptureParams device_info_;
   bool device_info_available_;
 
+  bool suspended_;
   VideoCaptureState state_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_H_