ImageCapture: Implement takePhoto() for Windows

media/capture/video/win/video_capture_device_win.h

Index: media/capture/video/win/video_capture_device_win.h
diff --git a/media/capture/video/win/video_capture_device_win.h b/media/capture/video/win/video_capture_device_win.h
index 12ae25b476d7660e1c964df2af7bb9e59cded767..35a7c4cf55e464e27dda2bf7c6f81900c991bdae 100644
--- a/media/capture/video/win/video_capture_device_win.h
+++ b/media/capture/video/win/video_capture_device_win.h
@@ -75,6 +75,7 @@ class VideoCaptureDeviceWin : public VideoCaptureDevice,
       const VideoCaptureParams& params,
       std::unique_ptr<VideoCaptureDevice::Client> client) override;
   void StopAndDeAllocate() override;
+  void TakePhoto(TakePhotoCallback callback) override;
 
  private:
   enum InternalState {
@@ -115,6 +116,8 @@ class VideoCaptureDeviceWin : public VideoCaptureDevice,
 
   base::TimeTicks first_ref_time_;
 
+  std::queue<TakePhotoCallback> take_photo_callbacks_;
+
   base::ThreadChecker thread_checker_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin);