Tab/Desktop Capture: Use requests instead of timer-based refreshing.

content/browser/media/capture/web_contents_video_capture_device.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.
 
 #ifndef CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
 #define CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 19 matching lines @@
  public:
   // Create a WebContentsVideoCaptureDevice instance from the given
   // |device_id|.  Returns NULL if |device_id| is invalid.
   static media::VideoCaptureDevice* Create(const std::string& device_id);
 
   ~WebContentsVideoCaptureDevice() override;
 
   // VideoCaptureDevice implementation.
   void AllocateAndStart(const media::VideoCaptureParams& params,
                         scoped_ptr<Client> client) override;
+  void RequestRefreshFrame() override;
   void StopAndDeAllocate() override;
 
  private:
   WebContentsVideoCaptureDevice(
       int render_process_id,
       int main_render_frame_id,
       bool enable_auto_throttling);
 
   const scoped_ptr<media::ScreenCaptureDeviceCore> core_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsVideoCaptureDevice);
 };
 
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_