Move StyleSheet to the oilpan heap using transition types.

Source/core/css/CSSStyleSheet.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 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 53 matching lines @@
     // Only these nodes can be parents of StyleSheets, and they need to call clearOwnerNode() when moved out of document.
     return !parentNode
         || parentNode->isDocumentNode()
         || parentNode->hasTagName(HTMLNames::linkTag)
         || parentNode->hasTagName(HTMLNames::styleTag)
         || parentNode->hasTagName(SVGNames::styleTag)
         || parentNode->nodeType() == Node::PROCESSING_INSTRUCTION_NODE;
 }
 #endif
 
-PassRefPtr<CSSStyleSheet> CSSStyleSheet::create(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet, CSSImportRule* ownerRule)
+PassRefPtrWillBeRawPtr<CSSStyleSheet> CSSStyleSheet::create(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet, CSSImportRule* ownerRule)
 {
-    return adoptRef(new CSSStyleSheet(sheet, ownerRule));
+    return adoptRefWillBeRefCountedGarbageCollected(new CSSStyleSheet(sheet, ownerRule));
 }
 
-PassRefPtr<CSSStyleSheet> CSSStyleSheet::create(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet, Node* ownerNode)
+PassRefPtrWillBeRawPtr<CSSStyleSheet> CSSStyleSheet::create(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet, Node* ownerNode)
 {
-    return adoptRef(new CSSStyleSheet(sheet, ownerNode, false, TextPosition::minimumPosition()));
+    return adoptRefWillBeRefCountedGarbageCollected(new CSSStyleSheet(sheet, ownerNode, false, TextPosition::minimumPosition()));
 }
 
-PassRefPtr<CSSStyleSheet> CSSStyleSheet::createInline(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet, Node* ownerNode, const TextPosition& startPosition)
+PassRefPtrWillBeRawPtr<CSSStyleSheet> CSSStyleSheet::createInline(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet, Node* ownerNode, const TextPosition& startPosition)
 {
     ASSERT(sheet);
-    return adoptRef(new CSSStyleSheet(sheet, ownerNode, true, startPosition));
+    return adoptRefWillBeRefCountedGarbageCollected(new CSSStyleSheet(sheet, ownerNode, true, startPosition));
 }
 
-PassRefPtr<CSSStyleSheet> CSSStyleSheet::createInline(Node* ownerNode, const KURL& baseURL, const TextPosition& startPosition, const String& encoding)
+PassRefPtrWillBeRawPtr<CSSStyleSheet> CSSStyleSheet::createInline(Node* ownerNode, const KURL& baseURL, const TextPosition& startPosition, const String& encoding)
 {
     CSSParserContext parserContext(ownerNode->document(), 0, baseURL, encoding);
     RefPtrWillBeRawPtr<StyleSheetContents> sheet = StyleSheetContents::create(baseURL.string(), parserContext);
-    return adoptRef(new CSSStyleSheet(sheet.release(), ownerNode, true, startPosition));
+    return adoptRefWillBeRefCountedGarbageCollected(new CSSStyleSheet(sheet.release(), ownerNode, true, startPosition));
 }
 
 CSSStyleSheet::CSSStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents> contents, CSSImportRule* ownerRule)
     : m_contents(contents)
     , m_isInlineStylesheet(false)
     , m_isDisabled(false)
     , m_ownerNode(0)
     , m_ownerRule(ownerRule)
     , m_startPosition(TextPosition::minimumPosition())
     , m_loadCompleted(false)
 {
     m_contents->registerClient(this);
 }
 
 CSSStyleSheet::CSSStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents> contents, Node* ownerNode, bool isInlineStylesheet, const TextPosition& startPosition)
     : m_contents(contents)
     , m_isInlineStylesheet(isInlineStylesheet)
     , m_isDisabled(false)
     , m_ownerNode(ownerNode)
-    , m_ownerRule(0)
+    , m_ownerRule(nullptr)
     , m_startPosition(startPosition)
     , m_loadCompleted(false)
 {
     ASSERT(isAcceptableCSSStyleSheetParent(ownerNode));
     m_contents->registerClient(this);
 }
 
 CSSStyleSheet::~CSSStyleSheet()
 {
+    // With oilpan the parent style sheet pointer is strong and the sheet and
+    // its RuleCSSOMWrappers die together and we don't need to clear them here.
+    // Also with oilpan the StyleSheetContents client pointers are weak and
+    // therefore do not need to be cleared here.
+#if !ENABLE(OILPAN)
     // For style rules outside the document, .parentStyleSheet can become null even if the style rule
     // is still observable from JavaScript. This matches the behavior of .parentNode for nodes, but
     // it's not ideal because it makes the CSSOM's behavior depend on the timing of garbage collection.
     for (unsigned i = 0; i < m_childRuleCSSOMWrappers.size(); ++i) {
         if (m_childRuleCSSOMWrappers[i])
             m_childRuleCSSOMWrappers[i]->setParentStyleSheet(0);
     }
 
     if (m_mediaCSSOMWrapper)
         m_mediaCSSOMWrapper->clearParentStyleSheet();
 
     m_contents->unregisterClient(this);
+#endif
 }
 
 void CSSStyleSheet::willMutateRules()
 {
     InspectorInstrumentation::willMutateRules(this);
     // If we are the only client it is safe to mutate.
     if (m_contents->hasOneClient() && !m_contents->isInMemoryCache()) {
         m_contents->clearRuleSet();
         if (m_contents->maybeCacheable())
             StyleEngine::removeSheet(m_contents.get());
@@ skipping 253 matching lines @@
     m_loadCompleted = m_ownerNode->sheetLoaded();
     return m_loadCompleted;
 }
 
 void CSSStyleSheet::startLoadingDynamicSheet()
 {
     m_loadCompleted = false;
     m_ownerNode->startLoadingDynamicSheet();
 }
 
+void CSSStyleSheet::trace(Visitor* visitor)
+{
+    visitor->trace(m_contents);
+    visitor->trace(m_mediaQueries);
+    visitor->trace(m_ownerRule);
+    visitor->trace(m_mediaCSSOMWrapper);
+    visitor->trace(m_childRuleCSSOMWrappers);
 }
+
+}