Make CSSParserContext be garbage collected.

third_party/WebKit/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 84 matching lines @@
                                            Node& ownerNode,
                                            const TextPosition& startPosition) {
   DCHECK(sheet);
   return new CSSStyleSheet(sheet, ownerNode, true, startPosition);
 }
 
 CSSStyleSheet* CSSStyleSheet::createInline(Node& ownerNode,
                                            const KURL& baseURL,
                                            const TextPosition& startPosition,
                                            const String& encoding) {
-  CSSParserContext parserContext(ownerNode.document(), nullptr, baseURL,
-                                 encoding);
+  CSSParserContext* parserContext =
+      new CSSParserContext(ownerNode.document(), baseURL, encoding);
   StyleSheetContents* sheet =
       StyleSheetContents::create(baseURL.getString(), parserContext);
   return new CSSStyleSheet(sheet, ownerNode, true, startPosition);
 }
 
 CSSStyleSheet::CSSStyleSheet(StyleSheetContents* contents,
                              CSSImportRule* ownerRule)
     : m_contents(contents),
       m_ownerRule(ownerRule),
       m_startPosition(TextPosition::minimumPosition()) {
@@ skipping 140 matching lines @@
   DCHECK(m_childRuleCSSOMWrappers.isEmpty() ||
          m_childRuleCSSOMWrappers.size() == m_contents->ruleCount());
 
   if (index > length()) {
     exceptionState.throwDOMException(
         IndexSizeError, "The index provided (" + String::number(index) +
                             ") is larger than the maximum index (" +
                             String::number(length()) + ").");
     return 0;
   }
-  CSSParserContext context(m_contents->parserContext(),
-                           UseCounter::getFrom(this));
+  const CSSParserContext* context =
+      CSSParserContext::create(m_contents->parserContext(), this);
   StyleRuleBase* rule =
       CSSParser::parseRule(context, m_contents.get(), ruleString);
 
   if (!rule) {
     exceptionState.throwDOMException(
         SyntaxError, "Failed to parse the rule '" + ruleString + "'.");
     return 0;
   }
   RuleMutationScope mutationScope(this);
 
@@ skipping 155 matching lines @@
   visitor->trace(m_deviceDependentMediaQueryResults);
   visitor->trace(m_ownerNode);
   visitor->trace(m_ownerRule);
   visitor->trace(m_mediaCSSOMWrapper);
   visitor->trace(m_childRuleCSSOMWrappers);
   visitor->trace(m_ruleListCSSOMWrapper);
   StyleSheet::trace(visitor);
 }
 
 }  // namespace blink