Pass implementation object to supplemental classes by reference

Source/modules/vibration/NavigatorVibration.h

Index: Source/modules/vibration/NavigatorVibration.h
diff --git a/Source/modules/vibration/NavigatorVibration.h b/Source/modules/vibration/NavigatorVibration.h
index b95a49b69679a6acfe049ec493477a0d68653a0f..48a83bab720b816918183f31c1d5287806dadf19 100644
--- a/Source/modules/vibration/NavigatorVibration.h
+++ b/Source/modules/vibration/NavigatorVibration.h
@@ -48,16 +48,16 @@ public:
     virtual void pageVisibilityChanged() OVERRIDE;
     virtual void didCommitLoad(Frame*) OVERRIDE;
 
-    static bool vibrate(Navigator*, unsigned time);
-    static bool vibrate(Navigator*, const VibrationPattern&);
-    static NavigatorVibration* from(Page*);
+    static bool vibrate(Navigator&, unsigned time);
+    static bool vibrate(Navigator&, const VibrationPattern&);
+    static NavigatorVibration& from(Page&);
 
     bool isVibrating() const { return m_isVibrating; }
 
     VibrationPattern pattern() const { return m_pattern; }
 
 private:
-    explicit NavigatorVibration(Page*);
+    explicit NavigatorVibration(Page&);
     static const char* supplementName();
 
     Timer<NavigatorVibration> m_timerStart;