Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/StyleEngine.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 184 matching lines @@
 
     TreeScopeStyleSheetCollection* ensureStyleSheetCollectionFor(TreeScope&);
     TreeScopeStyleSheetCollection* styleSheetCollectionFor(TreeScope&);
     bool shouldUpdateShadowTreeStyleSheetCollection(StyleResolverUpdateMode);
 
     void markTreeScopeDirty(TreeScope&);
 
     bool isMaster() const { return m_isMaster; }
     Document* master();
 
     typedef ListHashSet<TreeScope*, 16> TreeScopeSet;

[haraken, 2014/04/25 05:21:42]

Just to confirm: It is safe to use raw pointers to TreeScope because all the
TreeScopes are in the Document that keeps a persistent handle to this
StyleEngine. Right?

[Mads Ager (chromium), 2014/04/25 10:58:25]

Yes.

     static void insertTreeScopeInDocumentOrder(TreeScopeSet&, TreeScope*);
     void clearMediaQueryRuleSetOnTreeScopeStyleSheets(TreeScopeSet treeScopes);
 
     void createResolver();
 
     static PassRefPtrWillBeRawPtr<CSSStyleSheet> parseSheet(Element*, const String& text, TextPosition startPosition, bool createdByParser);
 
     Document& m_document;
     bool m_isMaster;
 
     // Track the number of currently loading top-level stylesheets needed for rendering.
     // Sheets loaded using the @import directive are not included in this count.
     // We use this count of pending sheets to detect when we can begin attaching
     // elements and when it is safe to execute scripts.
     int m_pendingStylesheets;
 
     mutable WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet> > m_injectedAuthorStyleSheets;
     mutable bool m_injectedStyleSheetCacheValid;
 
     WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet> > m_authorStyleSheets;
 
     DocumentStyleSheetCollection m_documentStyleSheetCollection;
-    WillBeHeapHashMap<TreeScope*, OwnPtrWillBeMember<ShadowTreeStyleSheetCollection> > m_styleSheetCollectionMap;
+    typedef WillBeHeapHashMap<RawPtrWillBeWeakMember<TreeScope>, OwnPtrWillBeMember<ShadowTreeStyleSheetCollection> > StyleSheetCollectionMap;
+    StyleSheetCollectionMap m_styleSheetCollectionMap;
 
     bool m_documentScopeDirty;
     TreeScopeSet m_dirtyTreeScopes;
     TreeScopeSet m_activeTreeScopes;
 
     String m_preferredStylesheetSetName;
     String m_selectedStylesheetSetName;
 
     bool m_usesSiblingRules;
     bool m_usesSiblingRulesOverride;
     bool m_usesFirstLineRules;
     bool m_usesFirstLetterRules;
     bool m_usesRemUnits;
     unsigned m_maxDirectAdjacentSelectors;
 
     bool m_ignorePendingStylesheets;
     bool m_didCalculateResolver;
     OwnPtrWillBeMember<StyleResolver> m_resolver;
 
     RefPtrWillBeMember<CSSFontSelector> m_fontSelector;
 
     WillBeHeapHashMap<AtomicString, RawPtrWillBeMember<StyleSheetContents> > m_textToSheetCache;
     WillBeHeapHashMap<RawPtrWillBeMember<StyleSheetContents>, AtomicString> m_sheetToTextCache;
 };
 
 }
 
 #endif