CSSValue Immediates: Replace CSSValue usage with const references

Source/core/css/resolver/ElementStyleResources.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 35 matching lines @@
 typedef WillBeHeapHashMap<CSSPropertyID, NullableCSSValue> PendingImagePropertyMap;
 
 // Holds information about resources, requested by stylesheets.
 // Lifetime: per-element style resolve.
 class ElementStyleResources {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(ElementStyleResources);
 public:
     ElementStyleResources();
 
-    PassRefPtr<StyleImage> styleImage(Document&, const TextLinkColors&, Color currentColor, CSSPropertyID, CSSValue);
+    PassRefPtr<StyleImage> styleImage(Document&, const TextLinkColors&, Color currentColor, CSSPropertyID, const CSSValue&);
 
     PassRefPtr<StyleImage> generatedOrPendingFromValue(CSSPropertyID, CSSImageGeneratorValue*);
     PassRefPtr<StyleImage> cachedOrPendingFromValue(Document&, CSSPropertyID, CSSImageValue&);
     PassRefPtr<StyleImage> setOrPendingFromValue(CSSPropertyID, CSSImageSetValue&);
     PassRefPtr<StyleImage> cursorOrPendingFromValue(CSSPropertyID, CSSCursorImageValue&);
 
     const PendingImagePropertyMap& pendingImageProperties() const { return m_pendingImageProperties; }
     const PendingSVGDocumentMap& pendingSVGDocuments() const { return m_pendingSVGDocuments; }
 
     void clearPendingImageProperties();
     void clearPendingSVGDocuments();
 
     float deviceScaleFactor() const { return m_deviceScaleFactor; }
     void setDeviceScaleFactor(float deviceScaleFactor) { m_deviceScaleFactor = deviceScaleFactor; }
 
     void addPendingSVGDocument(FilterOperation*, CSSSVGDocumentValue*);
 
 private:
     PendingImagePropertyMap m_pendingImageProperties;
     PendingSVGDocumentMap m_pendingSVGDocuments;
     float m_deviceScaleFactor;
 };
 
 } // namespace blink
 
 #endif // ElementStyleResources_h