Move StyleSheet to the oilpan heap using transition types.

Source/core/css/CSSStyleSheet.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010, 2012 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 31 matching lines @@
 class SecurityOrigin;
 class StyleSheetContents;
 
 enum StyleSheetUpdateType {
     PartialRuleUpdate,
     EntireStyleSheetUpdate
 };
 
 class CSSStyleSheet FINAL : public StyleSheet {
 public:
-    static PassRefPtr<CSSStyleSheet> create(PassRefPtrWillBeRawPtr<StyleSheetContents>, CSSImportRule* ownerRule = 0);
-    static PassRefPtr<CSSStyleSheet> create(PassRefPtrWillBeRawPtr<StyleSheetContents>, Node* ownerNode);
-    static PassRefPtr<CSSStyleSheet> createInline(Node*, const KURL&, const TextPosition& startPosition = TextPosition::minimumPosition(), const String& encoding = String());
-    static PassRefPtr<CSSStyleSheet> createInline(PassRefPtrWillBeRawPtr<StyleSheetContents>, Node* ownerNode, const TextPosition& startPosition = TextPosition::minimumPosition());
+    static PassRefPtrWillBeRawPtr<CSSStyleSheet> create(PassRefPtrWillBeRawPtr<StyleSheetContents>, CSSImportRule* ownerRule = 0);
+    static PassRefPtrWillBeRawPtr<CSSStyleSheet> create(PassRefPtrWillBeRawPtr<StyleSheetContents>, Node* ownerNode);
+    static PassRefPtrWillBeRawPtr<CSSStyleSheet> createInline(Node*, const KURL&, const TextPosition& startPosition = TextPosition::minimumPosition(), const String& encoding = String());
+    static PassRefPtrWillBeRawPtr<CSSStyleSheet> createInline(PassRefPtrWillBeRawPtr<StyleSheetContents>, Node* ownerNode, const TextPosition& startPosition = TextPosition::minimumPosition());
 
     virtual ~CSSStyleSheet();
 
     virtual CSSStyleSheet* parentStyleSheet() const OVERRIDE;
     virtual Node* ownerNode() const OVERRIDE { return m_ownerNode; }
     virtual MediaList* media() const OVERRIDE;
     virtual String href() const OVERRIDE;
     virtual String title() const OVERRIDE { return m_title; }
     virtual bool disabled() const OVERRIDE { return m_isDisabled; }
     virtual void setDisabled(bool) OVERRIDE;
@@ skipping 11 matching lines @@
 
     // For CSSRuleList.
     unsigned length() const;
     CSSRule* item(unsigned index);
 
     virtual void clearOwnerNode() OVERRIDE { didMutate(EntireStyleSheetUpdate); m_ownerNode = 0; }
     virtual CSSRule* ownerRule() const OVERRIDE { return m_ownerRule; }
     virtual KURL baseURL() const OVERRIDE;
     virtual bool isLoading() const OVERRIDE;
 
-    void clearOwnerRule() { m_ownerRule = 0; }
+    void clearOwnerRule() { m_ownerRule = nullptr; }
     Document* ownerDocument() const;
     MediaQuerySet* mediaQueries() const { return m_mediaQueries.get(); }
     void setMediaQueries(PassRefPtrWillBeRawPtr<MediaQuerySet>);
     void setTitle(const String& title) { m_title = title; }
 
     class RuleMutationScope {
         WTF_MAKE_NONCOPYABLE(RuleMutationScope);
     public:
         RuleMutationScope(CSSStyleSheet*);
         RuleMutationScope(CSSRule*);
@@ skipping 11 matching lines @@
 
     StyleSheetContents* contents() const { return m_contents.get(); }
 
     bool isInline() const { return m_isInlineStylesheet; }
     TextPosition startPositionInSource() const { return m_startPosition; }
 
     bool sheetLoaded();
     bool loadCompleted() const { return m_loadCompleted; }
     void startLoadingDynamicSheet();
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 private:
     CSSStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents>, CSSImportRule* ownerRule);
     CSSStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents>, Node* ownerNode, bool isInlineStylesheet, const TextPosition& startPosition);
 
     virtual bool isCSSStyleSheet() const OVERRIDE { return true; }
     virtual String type() const OVERRIDE { return "text/css"; }
 
     void reattachChildRuleCSSOMWrappers();
 
     bool canAccessRules() const;
 
-    RefPtrWillBePersistent<StyleSheetContents> m_contents;
+    RefPtrWillBeMember<StyleSheetContents> m_contents;
     bool m_isInlineStylesheet;
     bool m_isDisabled;
     String m_title;
-    RefPtrWillBePersistent<MediaQuerySet> m_mediaQueries;
+    RefPtrWillBeMember<MediaQuerySet> m_mediaQueries;
 
     Node* m_ownerNode;
-    // FIXME: oilpan: This is a back pointer from CSSImportRule, corresponding
-    // to the forward pointer on that, called m_styleSheetCSSOMWrapper. (It is
-    // not related to the m_parentStyleSheet pointer which is also typed as
-    // CSSStyleSheet, and which is inherited by CSSImportRule from CSSRule).
-    // Since m_styleSheetCSSOMWrapper is a RefPtr we know that this object
-    // cannot die before the CSSImportRule is destructed, which makes it OK to
-    // clear this from ~CSSImportRule. When this is on the GC heap we can make
-    // this a regular Member.
-    CSSRule* m_ownerRule;
+    RawPtrWillBeMember<CSSRule> m_ownerRule;
 
     TextPosition m_startPosition;
     bool m_loadCompleted;
 
-    mutable RefPtrWillBePersistent<MediaList> m_mediaCSSOMWrapper;
-    mutable WillBePersistentHeapVector<RefPtrWillBeMember<CSSRule> > m_childRuleCSSOMWrappers;
+    mutable RefPtrWillBeMember<MediaList> m_mediaCSSOMWrapper;
+    mutable WillBeHeapVector<RefPtrWillBeMember<CSSRule> > m_childRuleCSSOMWrappers;
     mutable OwnPtr<CSSRuleList> m_ruleListCSSOMWrapper;
 };
 
 inline CSSStyleSheet::RuleMutationScope::RuleMutationScope(CSSStyleSheet* sheet)
     : m_styleSheet(sheet)
 {
     if (m_styleSheet)
         m_styleSheet->willMutateRules();
 }
 
 inline CSSStyleSheet::RuleMutationScope::RuleMutationScope(CSSRule* rule)
     : m_styleSheet(rule ? rule->parentStyleSheet() : 0)
 {
     if (m_styleSheet)
         m_styleSheet->willMutateRules();
 }
 
 inline CSSStyleSheet::RuleMutationScope::~RuleMutationScope()
 {
     if (m_styleSheet)
         m_styleSheet->didMutateRules();
 }
 
 DEFINE_TYPE_CASTS(CSSStyleSheet, StyleSheet, sheet, sheet->isCSSStyleSheet(), sheet.isCSSStyleSheet());
 
 } // namespace
 
 #endif