Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/dom/ElementRareData.h

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 89 matching lines @@
         if (!m_shadow)
             m_shadow = ElementShadow::create();
         return *m_shadow;
     }
 
     NamedNodeMap* attributeMap() const { return m_attributeMap.get(); }
     void setAttributeMap(PassOwnPtr<NamedNodeMap> attributeMap) { m_attributeMap = attributeMap; }
 
     RenderStyle* computedStyle() const { return m_computedStyle.get(); }
     void setComputedStyle(PassRefPtr<RenderStyle> computedStyle) { m_computedStyle = computedStyle; }
-    void clearComputedStyle() { m_computedStyle = 0; }
+    void clearComputedStyle() { m_computedStyle = nullptr; }
 
     ClassList* classList() const { return m_classList.get(); }
     void setClassList(PassOwnPtr<ClassList> classList) { m_classList = classList; }
     void clearClassListValueForQuirksMode()
     {
         if (!m_classList)
             return;
         m_classList->clearValueForQuirksMode();
     }
 
@@ skipping 105 matching lines @@
     ASSERT(!m_backdrop);
 }
 
 inline bool ElementRareData::hasPseudoElements() const
 {
     return m_generatedBefore || m_generatedAfter || m_backdrop;
 }
 
 inline void ElementRareData::clearPseudoElements()
 {
-    setPseudoElement(BEFORE, 0);
-    setPseudoElement(AFTER, 0);
-    setPseudoElement(BACKDROP, 0);
+    setPseudoElement(BEFORE, nullptr);
+    setPseudoElement(AFTER, nullptr);
+    setPseudoElement(BACKDROP, nullptr);
 }
 
 inline void ElementRareData::setPseudoElement(PseudoId pseudoId, PassRefPtr<PseudoElement> element)
 {
     switch (pseudoId) {
     case BEFORE:
         if (m_generatedBefore)
             m_generatedBefore->dispose();
         m_generatedBefore = element;
         break;
@@ skipping 41 matching lines @@
     setChildrenAffectedByFirstChildRules(false);
     setChildrenAffectedByLastChildRules(false);
     setChildrenAffectedByDirectAdjacentRules(false);
     setChildrenAffectedByForwardPositionalRules(false);
     setChildrenAffectedByBackwardPositionalRules(false);
 }
 
 } // namespace
 
 #endif // ElementRareData_h