[CSS Regions] Add new regionOversetChange event

Source/core/dom/NamedFlow.h

 /*
  * Copyright (C) 2011 Adobe Systems Incorporated. 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.
@@ skipping 60 matching lines @@
     void setRenderer(RenderNamedFlowThread* parentFlowThread);
 
     enum FlowState {
         FlowStateCreated,
         FlowStateNull
     };
 
     FlowState flowState() const { return m_parentFlowThread ? FlowStateCreated : FlowStateNull; }
 
     void dispatchRegionLayoutUpdateEvent();
+    void dispatchRegionOversetChangeEvent();
 
 private:
     NamedFlow(PassRefPtr<NamedFlowCollection>, const AtomicString&);
 
     // EventTarget implementation.
     virtual void refEventTarget() { ref(); }
     virtual void derefEventTarget() { deref(); }
 
     virtual EventTargetData* eventTargetData() OVERRIDE;
     virtual EventTargetData* ensureEventTargetData() OVERRIDE;
 
     // The name of the flow thread as specified in CSS.
     AtomicString m_flowThreadName;
 
     RefPtr<NamedFlowCollection> m_flowManager;
     RenderNamedFlowThread* m_parentFlowThread;
 
     EventTargetData m_eventTargetData;
 };
 
 }
 
 #endif