Make CSSParserContext be garbage collected.

third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp

 // Copyright 2016 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 "modules/canvas2d/BaseRenderingContext2D.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/css/cssom/CSSURLImageValue.h"
 #include "core/css/parser/CSSParser.h"
@@ skipping 384 matching lines @@
 String BaseRenderingContext2D::filter() const {
   return state().unparsedFilter();
 }
 
 void BaseRenderingContext2D::setFilter(const String& filterString) {
   if (filterString == state().unparsedFilter())
     return;
 
   const CSSValue* filterValue =
       CSSParser::parseSingleValue(CSSPropertyFilter, filterString,
-                                  CSSParserContext(HTMLStandardMode, nullptr));
+                                  CSSParserContext::create(HTMLStandardMode));
 
   if (!filterValue || filterValue->isInitialValue() ||
       filterValue->isInheritedValue())
     return;
 
   modifiableState().setUnparsedFilter(filterString);
   modifiableState().setFilter(filterValue);
   snapshotStateForFilter();
 }
 
@@ skipping 1597 matching lines @@
       ExpensiveCanvasHeuristicParameters::ShadowFixedCost[index] *
           m_usageCounters.numBlurredShadows +
       ExpensiveCanvasHeuristicParameters::
               ShadowVariableCostPerAreaTimesShadowBlurSquared[index] *
           m_usageCounters.boundingBoxAreaTimesShadowBlurSquared;
 
   return basicCostOfDrawCalls + fillTypeAdjustment + shadowAdjustment;
 }
 
 }  // namespace blink