Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/ProcessingInstruction.cpp

 /*
  * Copyright (C) 2000 Peter Kelly (pmk@post.com)
  * Copyright (C) 2006, 2008, 2009 Apple 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 40 matching lines @@
 PassRefPtr<ProcessingInstruction> ProcessingInstruction::create(Document& document, const String& target, const String& data)
 {
     return adoptRef(new ProcessingInstruction(document, target, data));
 }
 
 ProcessingInstruction::~ProcessingInstruction()
 {
     if (m_sheet)
         m_sheet->clearOwnerNode();
 
+#if !ENABLE(OILPAN)
     if (inDocument())
         document().styleEngine()->removeStyleSheetCandidateNode(this);
+#endif
 }
 
 String ProcessingInstruction::nodeName() const
 {
     return m_target;
 }
 
 Node::NodeType ProcessingInstruction::nodeType() const
 {
     return PROCESSING_INSTRUCTION_NODE;
@@ skipping 171 matching lines @@
         m_sheet->clearOwnerNode();
         m_sheet = nullptr;
     }
 
     // If we're in document teardown, then we don't need to do any notification of our sheet's removal.
     if (document().isActive())
         document().removedStyleSheet(removedSheet.get());
 }
 
 } // namespace