Perf Tryjob: CSSValue refactor step 1

Source/modules/canvas2d/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 635 matching lines @@
 String CanvasRenderingContext2D::filter() const
 {
     return state().unparsedFilter();
 }
 
 void CanvasRenderingContext2D::setFilter(const String& filterString)
 {
     if (filterString == state().unparsedFilter())
         return;
 
-    RefPtrWillBeRawPtr<CSSValue> filterValue = CSSParser::parseSingleValue(CSSPropertyWebkitFilter, filterString, CSSParserContext(HTMLStandardMode, 0));
+    NullableCSSValue filterValue = CSSParser::parseSingleValue(CSSPropertyWebkitFilter, filterString, CSSParserContext(HTMLStandardMode, 0));
 
     if (!filterValue || filterValue->isInitialValue() || filterValue->isInheritedValue())
         return;
 
     modifiableState().setUnparsedFilter(filterString);
-    modifiableState().setFilter(filterValue.release());
+    modifiableState().setFilter(*filterValue);
 }
 
 PassRefPtrWillBeRawPtr<SVGMatrixTearOff> CanvasRenderingContext2D::currentTransform() const
 {
     return SVGMatrixTearOff::create(state().transform());
 }
 
 void CanvasRenderingContext2D::setCurrentTransform(PassRefPtrWillBeRawPtr<SVGMatrixTearOff> passMatrixTearOff)
 {
     RefPtrWillBeRawPtr<SVGMatrixTearOff> matrixTearOff = passMatrixTearOff;
@@ skipping 1590 matching lines @@
         if (imageType == CanvasRenderingContext2DState::NonOpaqueImage)
             return;
         if (alpha < 0xFF)
             return;
     }
 
     canvas()->buffer()->willOverwriteCanvas();
 }
 
 } // namespace blink