Prepare SVGElement references in Document for oilpan

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 1395 matching lines @@
 
     RefPtrWillBeMember<Document> m_templateDocument;
     // With Oilpan the templateDocument and the templateDocumentHost
     // live and die together. Without Oilpan, the templateDocumentHost
     // is a manually managed backpointer from m_templateDocument.
     RawPtrWillBeMember<Document> m_templateDocumentHost;
 
     Timer<Document> m_didAssociateFormControlsTimer;
     WillBeHeapHashSet<RefPtrWillBeMember<Element> > m_associatedFormControls;
 
-    HashSet<SVGUseElement*> m_useElementsNeedingUpdate;
-    HashSet<Element*> m_layerUpdateSVGFilterElements;
+    WillBeHeapHashSet<RawPtrWillBeMember<SVGUseElement> > m_useElementsNeedingUpdate;
+    WillBeHeapHashSet<RawPtrWillBeMember<Element> > m_layerUpdateSVGFilterElements;

[haraken, 2014/06/17 01:09:29]

These elements are guaranteed to exist in the same tree, so it makes sense to
use strong pointers. Makes sense.

 
     bool m_hasViewportUnits;
 
     typedef WillBeHeapHashSet<RawPtrWillBeWeakMember<DocumentVisibilityObserver> > DocumentVisibilityObserverSet;
     DocumentVisibilityObserverSet m_visibilityObservers;
 
     int m_styleRecalcElementCounter;
 };
 
 inline bool Document::shouldOverrideLegacyDescription(ViewportDescription::Type origin)
@@ skipping 33 matching lines @@
 inline bool Node::isDocumentNode() const
 {
     return this == document();
 }
 
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace WebCore
 
 #endif // Document_h