Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/html/PluginDocument.cpp

 /*
  * Copyright (C) 2006, 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 36 matching lines @@
 class PluginDocumentParser : public RawDataDocumentParser {
 public:
     static PassRefPtr<PluginDocumentParser> create(PluginDocument* document)
     {
         return adoptRef(new PluginDocumentParser(document));
     }
 
 private:
     PluginDocumentParser(Document* document)
         : RawDataDocumentParser(document)
-        , m_embedElement(0)
+        , m_embedElement(nullptr)
     {
     }
 
     virtual void appendBytes(const char*, size_t) OVERRIDE;
 
     virtual void finish() OVERRIDE;
 
     void createDocumentStructure();
 
     PluginView* pluginView() const;
@@ skipping 59 matching lines @@
 }
 
 void PluginDocumentParser::finish()
 {
     if (PluginView* view = pluginView()) {
         const ResourceError& error = document()->loader()->mainDocumentError();
         if (error.isNull())
             view->didFinishLoading();
         else
             view->didFailLoading(error);
-        m_embedElement = 0;
+        m_embedElement = nullptr;
     }
     RawDataDocumentParser::finish();
 }
 
 PluginView* PluginDocumentParser::pluginView() const
 {
     if (Widget* widget = toPluginDocument(document())->pluginWidget()) {
         ASSERT_WITH_SECURITY_IMPLICATION(widget->isPluginContainer());
         return toPluginView(widget);
     }
@@ skipping 23 matching lines @@
 }
 
 Node* PluginDocument::pluginNode()
 {
     return m_pluginNode.get();
 }
 
 void PluginDocument::detach(const AttachContext& context)
 {
     // Release the plugin node so that we don't have a circular reference.
-    m_pluginNode = 0;
+    m_pluginNode = nullptr;
     HTMLDocument::detach(context);
 }
 
 void PluginDocument::cancelManualPluginLoad()
 {
     // PluginDocument::cancelManualPluginLoad should only be called once, but there are issues
     // with how many times we call beforeload on object elements. <rdar://problem/8441094>.
     if (!shouldLoadPluginManually())
         return;
 
     DocumentLoader* documentLoader = frame()->loader().documentLoader();
     documentLoader->cancelMainResourceLoad(ResourceError::cancelledError(documentLoader->request().url()));
     setShouldLoadPluginManually(false);
 }
 
 }