Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/dom/CharacterData.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. 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 177 matching lines @@
 void CharacterData::didModifyData(const String& oldData)
 {
     if (OwnPtr<MutationObserverInterestGroup> mutationRecipients = MutationObserverInterestGroup::createForCharacterDataMutation(*this))
         mutationRecipients->enqueueMutationRecord(MutationRecord::createCharacterData(this, oldData));
 
     if (parentNode())
         parentNode()->childrenChanged();
 
     if (!isInShadowTree()) {
         if (document().hasListenerType(Document::DOMCHARACTERDATAMODIFIED_LISTENER))
-            dispatchScopedEvent(MutationEvent::create(EventTypeNames::DOMCharacterDataModified, true, 0, oldData, m_data));
+            dispatchScopedEvent(MutationEvent::create(EventTypeNames::DOMCharacterDataModified, true, nullptr, oldData, m_data));
         dispatchSubtreeModifiedEvent();
     }
     InspectorInstrumentation::characterDataModified(this);
 }
 
 int CharacterData::maxCharacterOffset() const
 {
     return static_cast<int>(length());
 }
 
 bool CharacterData::offsetInCharacters() const
 {
     return true;
 }
 
 } // namespace WebCore