Move CSSRuleList to the garbage collected heap

Source/core/frame/DOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 1260 matching lines @@
 }
 
 PassRefPtr<CSSStyleDeclaration> DOMWindow::getComputedStyle(Element* elt, const String& pseudoElt) const
 {
     if (!elt)
         return nullptr;
 
     return CSSComputedStyleDeclaration::create(elt, false, pseudoElt);
 }
 
-PassRefPtr<CSSRuleList> DOMWindow::getMatchedCSSRules(Element* element, const String& pseudoElement) const
+PassRefPtrWillBeRawPtr<CSSRuleList> DOMWindow::getMatchedCSSRules(Element* element, const String& pseudoElement) const
 {
     UseCounter::count(document(), UseCounter::GetMatchedCSSRules);
     if (!element)
         return nullptr;
 
     if (!isCurrentlyDisplayedInFrame())
         return nullptr;
 
     unsigned colonStart = pseudoElement[0] == ':' ? (pseudoElement[1] == ':' ? 2 : 1) : 0;
     CSSSelector::PseudoType pseudoType = CSSSelector::parsePseudoType(AtomicString(pseudoElement.substring(colonStart)));
@@ skipping 522 matching lines @@
     return static_cast<DOMWindowLifecycleNotifier&>(LifecycleContext<DOMWindow>::lifecycleNotifier());
 }
 
 PassOwnPtr<LifecycleNotifier<DOMWindow> > DOMWindow::createLifecycleNotifier()
 {
     return DOMWindowLifecycleNotifier::create(this);
 }
 
 
 } // namespace WebCore