Make CSSParserContext be garbage collected.

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 428 matching lines @@
 }
 
 bool FontFaceSet::resolveFontStyle(const String& fontString, Font& font) {
   if (fontString.isEmpty())
     return false;
 
   // Interpret fontString in the same way as the 'font' attribute of
   // CanvasRenderingContext2D.
   MutableStylePropertySet* parsedStyle =
       MutableStylePropertySet::create(HTMLStandardMode);
-  CSSParser::parseValue(parsedStyle, CSSPropertyFont, fontString, true, 0);
+  CSSParser::parseValue(parsedStyle, CSSPropertyFont, fontString, true);
   if (parsedStyle->isEmpty())
     return false;
 
   String fontValue = parsedStyle->getPropertyValue(CSSPropertyFont);
   if (fontValue == "inherit" || fontValue == "initial")
     return false;
 
   RefPtr<ComputedStyle> style = ComputedStyle::create();
 
   FontFamily fontFamily;
@@ skipping 101 matching lines @@
   visitor->trace(m_failedFonts);
   visitor->trace(m_nonCSSConnectedFaces);
   visitor->trace(m_asyncRunner);
   EventTargetWithInlineData::trace(visitor);
   Supplement<Document>::trace(visitor);
   SuspendableObject::trace(visitor);
   FontFace::LoadFontCallback::trace(visitor);
 }
 
 }  // namespace blink