Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/html/HTMLLinkElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google 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
@@ skipping 131 matching lines @@
 
 PassRefPtr<HTMLLinkElement> HTMLLinkElement::create(Document& document, bool createdByParser)
 {
     return adoptRef(new HTMLLinkElement(document, createdByParser));
 }
 
 HTMLLinkElement::~HTMLLinkElement()
 {
     m_link.clear();
 
+#if !ENABLE(OILPAN)
     if (inDocument())
         document().styleEngine()->removeStyleSheetCandidateNode(this);
+#endif
 
     linkLoadEventSender().cancelEvent(this);
 }
 
 void HTMLLinkElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     if (name == relAttr) {
         m_relAttribute = LinkRelAttribute(value);
         process();
     } else if (name == hrefAttr) {
@@ skipping 520 matching lines @@
 void LinkStyle::ownerRemoved()
 {
     if (m_sheet)
         clearSheet();
 
     if (styleSheetIsLoading())
         removePendingSheet(RemovePendingSheetNotifyLater);
 }
 
 } // namespace WebCore