Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/svg/SVGStaticStringList.cpp

 /*
  * Copyright (C) 2014 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 39 matching lines @@
 }
 
 void SVGStaticStringList::animationStarted()
 {
     ASSERT_NOT_REACHED();
 }
 
 PassRefPtr<NewSVGPropertyBase> SVGStaticStringList::createAnimatedValue()
 {
     ASSERT_NOT_REACHED();
-    return 0;
+    return nullptr;
 }
 
 void SVGStaticStringList::setAnimatedValue(PassRefPtr<NewSVGPropertyBase>)
 {
     ASSERT_NOT_REACHED();
 }
 
 void SVGStaticStringList::animationEnded()
 {
     ASSERT_NOT_REACHED();
@@ skipping 26 matching lines @@
 {
     TrackExceptionState es;
 
     m_value->setValueAsString(value, es);
 
     if (es.hadException())
         parseError = ParsingAttributeFailedError;
 }
 
 }