Convert XMLDocumentParser code to Use more reference

Source/core/dom/ScriptableDocumentParser.cpp

 /*
  * Copyright (C) 2010 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:
  * 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 13 matching lines @@
  */
 
 #include "config.h"
 #include "core/dom/ScriptableDocumentParser.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/Settings.h"
 
 namespace WebCore {
 
-ScriptableDocumentParser::ScriptableDocumentParser(Document* document, ParserContentPolicy parserContentPolicy)
+ScriptableDocumentParser::ScriptableDocumentParser(Document& document, ParserContentPolicy parserContentPolicy)
     : DecodedDataDocumentParser(document)
     , m_wasCreatedByScript(false)
     , m_parserContentPolicy(parserContentPolicy)
 {
-    if (!pluginContentIsAllowed(m_parserContentPolicy) && (!document->settings() || document->settings()->unsafePluginPastingEnabled()))
+    if (!pluginContentIsAllowed(m_parserContentPolicy) && (!document.settings() || document.settings()->unsafePluginPastingEnabled()))
         m_parserContentPolicy = allowPluginContent(m_parserContentPolicy);
 }
 
 };