Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/rendering/style/RenderStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. All rights reserved.
  *
  * 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.
  *
@@ skipping 686 matching lines @@
 void RenderStyle::setQuotes(PassRefPtr<QuotesData> q)
 {
     if (QuotesData::equals(rareInheritedData->quotes.get(), q.get()))
         return;
     rareInheritedData.access()->quotes = q;
 }
 
 void RenderStyle::clearCursorList()
 {
     if (rareInheritedData->cursorData)
-        rareInheritedData.access()->cursorData = 0;
+        rareInheritedData.access()->cursorData = nullptr;
 }
 
 void RenderStyle::addCallbackSelector(const String& selector)
 {
     if (!rareNonInheritedData->m_callbackSelectors.contains(selector))
         rareNonInheritedData.access()->m_callbackSelectors.append(selector);
 }
 
 void RenderStyle::clearContent()
 {
@@ skipping 871 matching lines @@
 }
 
 void RenderStyle::setBorderImageOutset(const BorderImageLengthBox& outset)
 {
     if (surround->border.m_image.outset() == outset)
         return;
     surround.access()->border.m_image.setOutset(outset);
 }
 
 } // namespace WebCore