Revert of Removed unused cricket::VideoCapturer methods

webrtc/media/base/capturemanager.h

Index: webrtc/media/base/capturemanager.h
diff --git a/webrtc/media/base/capturemanager.h b/webrtc/media/base/capturemanager.h
index 9445f27cf3db14ab9199a91d9b8e06fee3648c1a..93f8e18610d52018b83c7dd6cb2f0b5b658a5402 100644
--- a/webrtc/media/base/capturemanager.h
+++ b/webrtc/media/base/capturemanager.h
@@ -53,6 +53,15 @@
   virtual bool StopVideoCapture(VideoCapturer* video_capturer,
                                 const VideoFormat& format);
 
+  // Possibly restarts the capturer. If |options| is set to kRequestRestart,
+  // the CaptureManager chooses whether this request can be handled with the
+  // current state or if a restart is actually needed. If |options| is set to
+  // kForceRestart, the capturer is restarted.
+  virtual bool RestartVideoCapture(VideoCapturer* video_capturer,
+                                   const VideoFormat& previous_format,
+                                   const VideoFormat& desired_format,
+                                   RestartOptions options);
+
   virtual void AddVideoSink(VideoCapturer* video_capturer,
                             rtc::VideoSinkInterface<VideoFrame>* sink);
   virtual void RemoveVideoSink(VideoCapturer* video_capturer,