Make CSSParserContext be garbage collected.

third_party/WebKit/Source/core/css/StylePropertySet.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2011 Research In Motion Limited. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. 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
@@ skipping 366 matching lines @@
   setProperty(CSSProperty(propertyID, *CSSIdentifierValue::create(identifier),
                           important));
   return true;
 }
 
 void MutableStylePropertySet::parseDeclarationList(
     const String& styleDeclaration,
     StyleSheetContents* contextStyleSheet) {
   m_propertyVector.clear();
 
-  CSSParserContext context(cssParserMode(),
-                           UseCounter::getFrom(contextStyleSheet));
+  CSSParserContext* context;
   if (contextStyleSheet) {
-    context = contextStyleSheet->parserContext();
-    context.setMode(cssParserMode());
+    context = CSSParserContext::create(contextStyleSheet->parserContext(),
+                                       contextStyleSheet);
+    context->setMode(cssParserMode());
+  } else {
+    context = new CSSParserContext(cssParserMode());
   }
 
   CSSParser::parseDeclarationList(context, this, styleDeclaration);
 }
 
 bool MutableStylePropertySet::addParsedProperties(
     const HeapVector<CSSProperty, 256>& properties) {
   bool changed = false;
   m_propertyVector.reserveCapacity(m_propertyVector.size() + properties.size());
   for (unsigned i = 0; i < properties.size(); ++i)
@@ skipping 208 matching lines @@
 
 MutableStylePropertySet* MutableStylePropertySet::create(
     const CSSProperty* properties,
     unsigned count) {
   return new MutableStylePropertySet(properties, count);
 }
 
 DEFINE_TRACE(CSSLazyPropertyParser) {}
 
 }  // namespace blink