Fix event passing to overlay scrollbars when over a plugin

Source/core/page/EventHandler.h

 /*
  * Copyright (C) 2006, 2007, 2009, 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 255 matching lines @@
 
     bool dispatchDragSrcEvent(const AtomicString& eventType, const PlatformMouseEvent&);
 
     bool dragHysteresisExceeded(const FloatPoint&) const;
     bool dragHysteresisExceeded(const IntPoint&) const;
 
     bool passMousePressEventToSubframe(MouseEventWithHitTestResults&, LocalFrame* subframe);
     bool passMouseMoveEventToSubframe(MouseEventWithHitTestResults&, LocalFrame* subframe, HitTestResult* hoveredNode = 0);
     bool passMouseReleaseEventToSubframe(MouseEventWithHitTestResults&, LocalFrame* subframe);
 
-    bool passMousePressEventToScrollbar(MouseEventWithHitTestResults&, Scrollbar*);
+    bool passMousePressEventToScrollbar(MouseEventWithHitTestResults&);
 
     bool passWidgetMouseDownEventToWidget(const MouseEventWithHitTestResults&);
 
     bool passWheelEventToWidget(const PlatformWheelEvent&, Widget*);
 
     void defaultSpaceEventHandler(KeyboardEvent*);
     void defaultBackspaceEventHandler(KeyboardEvent*);
     void defaultTabEventHandler(KeyboardEvent*);
     void defaultEscapeEventHandler(KeyboardEvent*);
     void defaultArrowEventHandler(FocusType, KeyboardEvent*);
@@ skipping 100 matching lines @@
     bool m_longTapShouldInvokeContextMenu;
 
     Timer<EventHandler> m_activeIntervalTimer;
     double m_lastShowPressTimestamp;
     RefPtrWillBePersistent<Element> m_lastDeferredTapElement;
 };
 
 } // namespace WebCore
 
 #endif // EventHandler_h