Standardize usage of virtual/override/final in remoting/

remoting/host/ipc_video_frame_capturer.h

Index: remoting/host/ipc_video_frame_capturer.h
diff --git a/remoting/host/ipc_video_frame_capturer.h b/remoting/host/ipc_video_frame_capturer.h
index db27f9886b3eaf6e2d4d181176c5865e330694aa..67bfe100f6b41423fd4e38318aec04662bbf5470 100644
--- a/remoting/host/ipc_video_frame_capturer.h
+++ b/remoting/host/ipc_video_frame_capturer.h
@@ -20,11 +20,11 @@ class IpcVideoFrameCapturer : public webrtc::DesktopCapturer {
  public:
   explicit IpcVideoFrameCapturer(
       scoped_refptr<DesktopSessionProxy> desktop_session_proxy);
-  virtual ~IpcVideoFrameCapturer();
+  ~IpcVideoFrameCapturer() override;
 
   // webrtc::DesktopCapturer interface.
-  virtual void Start(Callback* callback) override;
-  virtual void Capture(const webrtc::DesktopRegion& region) override;
+  void Start(Callback* callback) override;
+  void Capture(const webrtc::DesktopRegion& region) override;
 
   // Called when a video |frame| has been captured.
   void OnCaptureCompleted(scoped_ptr<webrtc::DesktopFrame> frame);