Fix some chromium-style warnings in webrtc/modules/bitrate_controller/

BUG=163
R=pwestin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1903004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4442 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
index e3e2639..4c891d9 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
@@ -34,16 +34,16 @@
   explicit BitrateControllerImpl();
   virtual ~BitrateControllerImpl();
 
-  virtual bool AvailableBandwidth(uint32_t* bandwidth) const;
+  virtual bool AvailableBandwidth(uint32_t* bandwidth) const OVERRIDE;
 
-  virtual RtcpBandwidthObserver* CreateRtcpBandwidthObserver();
+  virtual RtcpBandwidthObserver* CreateRtcpBandwidthObserver() OVERRIDE;
 
   virtual void SetBitrateObserver(BitrateObserver* observer,
                                   const uint32_t start_bitrate,
                                   const uint32_t min_bitrate,
-                                  const uint32_t max_bitrate);
+                                  const uint32_t max_bitrate) OVERRIDE;
 
-  virtual void RemoveBitrateObserver(BitrateObserver* observer);
+  virtual void RemoveBitrateObserver(BitrateObserver* observer) OVERRIDE;
 
  protected:
   struct BitrateConfiguration {