Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/css/MediaQueryListListener.h

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  *  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,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 17 matching lines @@
 
 class MediaQueryList;
 
 // See http://dev.w3.org/csswg/cssom-view/#the-mediaquerylist-interface
 
 class MediaQueryListListener : public RefCounted<MediaQueryListListener> {
 public:
     static PassRefPtr<MediaQueryListListener> create(const ScriptValue& value)
     {
         if (!value.isFunction())
-            return 0;
+            return nullptr;
         return adoptRef(new MediaQueryListListener(value));
     }
     void queryChanged(ScriptState*, MediaQueryList*);
 
     bool operator==(const MediaQueryListListener& other) const { return m_value == other.m_value; }
 
 private:
     MediaQueryListListener(const ScriptValue& value) : m_value(value) { }
 
     ScriptValue m_value;
 };
 
 }
 
 #endif // MediaQueryListListener_h