CSSValue Immediates: Replace CSSValue usage with const references

Source/modules/canvas2d/CanvasRenderingContext2DState.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 "config.h"
 
 #include "modules/canvas2d/CanvasRenderingContext2DState.h"
 
 #include "core/css/CSSFontSelector.h"
 #include "core/css/resolver/FilterOperationResolver.h"
@@ skipping 416 matching lines @@
     m_shadowBlur = shadowBlur;
     shadowParameterChanged();
 }
 
 void CanvasRenderingContext2DState::setShadowColor(SkColor shadowColor)
 {
     m_shadowColor = shadowColor;
     shadowParameterChanged();
 }
 
-void CanvasRenderingContext2DState::setFilter(CSSValue filterValue)
+void CanvasRenderingContext2DState::setFilter(const CSSValue& filterValue)
 {
     m_filterValue = filterValue;
     m_resolvedFilter.clear();
 }
 
 void CanvasRenderingContext2DState::setGlobalComposite(SkXfermode::Mode mode)
 {
     m_strokePaint.setXfermodeMode(mode);
     m_fillPaint.setXfermodeMode(mode);
     m_imagePaint.setXfermodeMode(mode);
@@ skipping 75 matching lines @@
         paint->setLooper(0);
         paint->setImageFilter(shadowAndForegroundImageFilter());
         return paint;
     }
     paint->setLooper(shadowAndForegroundDrawLooper());
     paint->setImageFilter(0);
     return paint;
 }
 
 } // blink