Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/html/HTMLStyleElement.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, 2010 Apple Inc. All rights reserved.
  *           (C) 2007 Rob Buis (buis@kde.org)
  *
  * 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
@@ skipping 40 matching lines @@
     , m_loadedSheet(false)
     , m_scopedStyleRegistrationState(NotRegistered)
 {
     ScriptWrappable::init(this);
 }
 
 HTMLStyleElement::~HTMLStyleElement()
 {
     // During tear-down, willRemove isn't called, so m_scopedStyleRegistrationState may still be RegisteredAsScoped or RegisteredInShadowRoot here.
     // Therefore we can't ASSERT(m_scopedStyleRegistrationState == NotRegistered).
+#if ENABLE(OILPAN)
+    // Remove this once StyleSheet has a strong pointer to its owner.
+    if (m_sheet)
+        m_sheet->clearOwnerNode();
+#else
     StyleElement::clearDocumentData(document(), this);
+#endif
 
     styleLoadEventSender().cancelEvent(this);
 }
 
 PassRefPtr<HTMLStyleElement> HTMLStyleElement::create(Document& document, bool createdByParser)
 {
     return adoptRef(new HTMLStyleElement(document, createdByParser));
 }
 
 void HTMLStyleElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
@@ skipping 209 matching lines @@
     return m_sheet->disabled();
 }
 
 void HTMLStyleElement::setDisabled(bool setDisabled)
 {
     if (CSSStyleSheet* styleSheet = sheet())
         styleSheet->setDisabled(setDisabled);
 }
 
 }