Change various helper classes to transition types to get CSSValue entirely onto the gc heap.

Source/core/css/StyleRuleImport.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2005, 2006, 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.
  *
@@ skipping 13 matching lines @@
 
 #include "FetchInitiatorTypeNames.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/dom/Document.h"
 #include "core/fetch/CSSStyleSheetResource.h"
 #include "core/fetch/FetchRequest.h"
 #include "core/fetch/ResourceFetcher.h"
 
 namespace WebCore {
 
-PassRefPtrWillBeRawPtr<StyleRuleImport> StyleRuleImport::create(const String& href, PassRefPtr<MediaQuerySet> media)
+PassRefPtrWillBeRawPtr<StyleRuleImport> StyleRuleImport::create(const String& href, PassRefPtrWillBeRawPtr<MediaQuerySet> media)
 {
     return adoptRefWillBeNoop(new StyleRuleImport(href, media));
 }
 
-StyleRuleImport::StyleRuleImport(const String& href, PassRefPtr<MediaQuerySet> media)
+StyleRuleImport::StyleRuleImport(const String& href, PassRefPtrWillBeRawPtr<MediaQuerySet> media)
     : StyleRuleBase(Import)
     , m_parentStyleSheet(nullptr)
     , m_styleSheetClient(this)
     , m_strHref(href)
     , m_mediaQueries(media)
     , m_resource(0)
     , m_loading(false)
 {
     if (!m_mediaQueries)
         m_mediaQueries = MediaQuerySet::create(String());
 }
 
 StyleRuleImport::~StyleRuleImport()
 {
 #if !ENABLE(OILPAN)
     if (m_styleSheet)
         m_styleSheet->clearOwnerRule();
 #endif
     if (m_resource)
         m_resource->removeClient(&m_styleSheetClient);
 }
 
 void StyleRuleImport::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_parentStyleSheet);
+    visitor->trace(m_mediaQueries);
     visitor->trace(m_styleSheet);
     StyleRuleBase::traceAfterDispatch(visitor);
 }
 
 void StyleRuleImport::setCSSStyleSheet(const String& href, const KURL& baseURL, const String& charset, const CSSStyleSheetResource* cachedStyleSheet)
 {
     if (m_styleSheet)
         m_styleSheet->clearOwnerRule();
 
     CSSParserContext context = m_parentStyleSheet ? m_parentStyleSheet->parserContext() : strictCSSParserContext();
@@ skipping 55 matching lines @@
         // removed from the pending sheet count, so let the doc know
         // the sheet being imported is pending.
         if (m_parentStyleSheet && m_parentStyleSheet->loadCompleted() && rootSheet == m_parentStyleSheet)
             m_parentStyleSheet->startLoadingDynamicSheet();
         m_loading = true;
         m_resource->addClient(&m_styleSheetClient);
     }
 }
 
 } // namespace WebCore