Make CSSParserContext be garbage collected.

third_party/WebKit/Source/core/html/canvas/CanvasFontCache.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/html/canvas/CanvasFontCache.h"
 
 #include "core/css/parser/CSSParser.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Document.h"
 #include "core/style/ComputedStyle.h"
@@ skipping 70 matching lines @@
 MutableStylePropertySet* CanvasFontCache::parseFont(const String& fontString) {
   MutableStylePropertySet* parsedStyle;
   MutableStylePropertyMap::iterator i = m_fetchedFonts.find(fontString);
   if (i != m_fetchedFonts.end()) {
     ASSERT(m_fontLRUList.contains(fontString));
     parsedStyle = i->value;
     m_fontLRUList.remove(fontString);
     m_fontLRUList.add(fontString);
   } else {
     parsedStyle = MutableStylePropertySet::create(HTMLStandardMode);
-    CSSParser::parseValue(parsedStyle, CSSPropertyFont, fontString, true, 0);
+    CSSParser::parseValue(parsedStyle, CSSPropertyFont, fontString, true);
     if (parsedStyle->isEmpty())
       return nullptr;
     // According to
     // http://lists.w3.org/Archives/Public/public-html/2009Jul/0947.html,
     // the "inherit" and "initial" values must be ignored.
     const CSSValue* fontValue =
         parsedStyle->getPropertyCSSValue(CSSPropertyFontSize);
     if (fontValue &&
         (fontValue->isInitialValue() || fontValue->isInheritedValue()))
       return nullptr;
@@ skipping 45 matching lines @@
   m_fontLRUList.clear();
   m_fontsResolvedUsingDefaultStyle.clear();
 }
 
 DEFINE_TRACE(CanvasFontCache) {
   visitor->trace(m_fetchedFonts);
   visitor->trace(m_document);
 }
 
 }  // namespace blink