Introduce DEFINE_ELEMENT_DATA_TYPE_CASTS, and use it

Source/core/dom/ElementData.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 65 matching lines @@
     , m_classNames(other.m_classNames)
     , m_idForStyleResolution(other.m_idForStyleResolution)
 {
     // NOTE: The inline style is copied by the subclass copy constructor since we don't know what to do with it here.
 }
 
 #if ENABLE(OILPAN)
 void ElementData::finalizeGarbageCollectedObject()
 {
     if (m_isUnique)
-        static_cast<UniqueElementData*>(this)->~UniqueElementData();
+        toUniqueElementData(this)->~UniqueElementData();
     else
-        static_cast<ShareableElementData*>(this)->~ShareableElementData();
+        toShareableElementData(this)->~ShareableElementData();
 }
 #else
 void ElementData::destroy()
 {
     if (m_isUnique)
-        delete static_cast<UniqueElementData*>(this);
+        delete toUniqueElementData(this);
     else
-        delete static_cast<ShareableElementData*>(this);
+        delete toShareableElementData(this);
 }
 #endif
 
 PassRefPtrWillBeRawPtr<UniqueElementData> ElementData::makeUniqueCopy() const
 {
     if (isUnique())
-        return adoptRefWillBeNoop(new UniqueElementData(static_cast<const UniqueElementData&>(*this)));
-    return adoptRefWillBeNoop(new UniqueElementData(static_cast<const ShareableElementData&>(*this)));
+        return adoptRefWillBeNoop(new UniqueElementData(toUniqueElementData(*this)));
+    return adoptRefWillBeNoop(new UniqueElementData(toShareableElementData(*this)));
 }
 
 bool ElementData::isEquivalent(const ElementData* other) const
 {
     AttributeCollection attributes = this->attributes();
     if (!other)
         return attributes.isEmpty();
 
     AttributeCollection otherAttributes = other->attributes();
     if (attributes.size() != otherAttributes.size())
         return false;
 
     AttributeCollection::const_iterator end = attributes.end();
     for (AttributeCollection::const_iterator it = attributes.begin(); it != end; ++it) {
         const Attribute* otherAttr = otherAttributes.find(it->name());
         if (!otherAttr || it->value() != otherAttr->value())
             return false;
     }
     return true;
 }
 
 void ElementData::trace(Visitor* visitor)
 {
     if (m_isUnique)
-        static_cast<UniqueElementData*>(this)->traceAfterDispatch(visitor);
+        toUniqueElementData(this)->traceAfterDispatch(visitor);
     else
-        static_cast<ShareableElementData*>(this)->traceAfterDispatch(visitor);
+        toShareableElementData(this)->traceAfterDispatch(visitor);
 }
 
 void ElementData::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_inlineStyle);
 }
 
 ShareableElementData::ShareableElementData(const Vector<Attribute>& attributes)
     : ElementData(attributes.size())
 {
@@ skipping 80 matching lines @@
     return 0;
 }
 
 void UniqueElementData::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_presentationAttributeStyle);
     ElementData::traceAfterDispatch(visitor);
 }
 
 } // namespace blink