Selectively disable rubber banding on mac.

Source/platform/mac/ScrollAnimatorMac.h

 /*
  * Copyright (C) 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 71 matching lines @@
     Timer<ScrollAnimatorMac> m_initialScrollbarPaintTimer;
 
     void sendContentAreaScrolledTimerFired(Timer<ScrollAnimatorMac>*);
     Timer<ScrollAnimatorMac> m_sendContentAreaScrolledTimer;
     FloatSize m_contentAreaScrolledTimerScrollDelta;
 
     virtual bool scroll(ScrollbarOrientation, ScrollGranularity, float step, float delta) OVERRIDE;
     virtual void scrollToOffsetWithoutAnimation(const FloatPoint&) OVERRIDE;
 
 #if USE(RUBBER_BANDING)
-    virtual bool handleWheelEvent(const PlatformWheelEvent&) OVERRIDE;
+    virtual bool handleWheelEvent(const PlatformWheelEvent&, bool canRubberbandLeft, bool canRubberbandRight) OVERRIDE;
 #endif
 
     virtual void handleWheelEventPhase(PlatformWheelEventPhase) OVERRIDE;
 
     virtual void cancelAnimations() OVERRIDE;
     virtual void setIsActive() OVERRIDE;
 
     virtual void notifyPositionChanged(const FloatSize& delta) OVERRIDE;
     virtual void contentAreaWillPaint() const OVERRIDE;
     virtual void mouseEnteredContentArea() const OVERRIDE;
@@ skipping 50 matching lines @@
 #endif
 
     bool m_haveScrolledSincePageLoad;
     bool m_needsScrollerStyleUpdate;
     IntRect m_visibleScrollerThumbRect;
 };
 
 } // namespace WebCore
 
 #endif // ScrollAnimatorMac_h