[CSS Regions] Add new regionOversetChange event

Source/core/rendering/RenderRegion.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 64 matching lines @@
     PassOwnPtr<RenderBoxRegionInfo> takeRenderBoxRegionInfo(const RenderBox*);
     void removeRenderBoxRegionInfo(const RenderBox*);
 
     void deleteAllRenderBoxRegionInfo();
 
     bool isFirstRegion() const;
     bool isLastRegion() const;
 
     void clearObjectStyleInRegion(const RenderObject*);
 
-    enum RegionState {
-        RegionUndefined,
-        RegionEmpty,
-        RegionFit,
-        RegionOverset
-    };
-
-    RegionState regionState() const { return isValid() ? m_regionState : RegionUndefined; }
-    void setRegionState(RegionState regionState) { m_regionState = regionState; }
+    RegionOversetState regionOversetState() const;
+    void setRegionOversetState(RegionOversetState);
     
     // These methods represent the width and height of a "page" and for a RenderRegion they are just the
     // content width and content height of a region. For RenderRegionSets, however, they will be the width and
     // height of a single column or page in the set.
     virtual LayoutUnit pageLogicalWidth() const;
     virtual LayoutUnit pageLogicalHeight() const;
     LayoutUnit maxPageLogicalHeight() const;
 
     LayoutUnit logicalTopOfFlowThreadContentRect(const LayoutRect&) const;
     LayoutUnit logicalBottomOfFlowThreadContentRect(const LayoutRect&) const;
@@ skipping 86 matching lines @@
         RefPtr<RenderStyle> style;
         // True if the computed style in region is cached.
         bool cached;
     };
     typedef HashMap<const RenderObject*, ObjectRegionStyleInfo > RenderObjectRegionStyleMap;
     RenderObjectRegionStyleMap m_renderObjectRegionStyle;
 
     bool m_isValid : 1;
     bool m_hasCustomRegionStyle : 1;
     bool m_hasAutoLogicalHeight : 1;
-    RegionState m_regionState;
 };
 
 inline RenderRegion* toRenderRegion(RenderObject* object)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderRegion());
     return static_cast<RenderRegion*>(object);
 }
 
 inline const RenderRegion* toRenderRegion(const RenderObject* object)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderRegion());
     return static_cast<const RenderRegion*>(object);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toRenderRegion(const RenderRegion*);
 
 } // namespace WebCore
 
 #endif // RenderRegion_h