Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/editing/EditorCommand.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Igalia S.L.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 1649 matching lines @@
 }
 
 Editor::Command::Command()
     : m_command(0)
 {
 }
 
 Editor::Command::Command(const EditorInternalCommand* command, EditorCommandSource source, PassRefPtr<Frame> frame)
     : m_command(command)
     , m_source(source)
-    , m_frame(command ? frame : 0)
+    , m_frame(command ? frame : nullptr)
 {
     // Use separate assertions so we can tell which bad thing happened.
     if (!command)
         ASSERT(!m_frame);
     else
         ASSERT(m_frame);
 }
 
 bool Editor::Command::execute(const String& parameter, Event* triggeringEvent) const
 {
@@ skipping 49 matching lines @@
         return m_command->state(*m_frame, triggeringEvent) == TrueTriState ? "true" : "false";
     return m_command->value(*m_frame, triggeringEvent);
 }
 
 bool Editor::Command::isTextInsertion() const
 {
     return m_command && m_command->isTextInsertion;
 }
 
 } // namespace WebCore