Made StylePropertySet::getPropertyCSSValue return a const CSSValue*

third_party/WebKit/Source/core/css/StylePropertySet.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2008, 2012 Apple 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 71 matching lines @@
     unsigned propertyCount() const;
     bool isEmpty() const;
     PropertyReference propertyAt(unsigned index) const { return PropertyReference(*this, index); }
 
     template<typename T> // CSSPropertyID or AtomicString
     int findPropertyIndex(T property) const;
 
     bool hasProperty(CSSPropertyID property) const { return findPropertyIndex(property) != -1; }
 
     template<typename T> // CSSPropertyID or AtomicString
-    CSSValue* getPropertyCSSValue(T property) const;
+    const CSSValue* getPropertyCSSValue(T property) const;
 
     template<typename T> // CSSPropertyID or AtomicString
     String getPropertyValue(T property) const;
 
     template<typename T> // CSSPropertyID or AtomicString
     bool propertyIsImportant(T property) const;
 
     bool shorthandIsImportant(CSSPropertyID) const;
     bool shorthandIsImportant(AtomicString customPropertyName) const;
 
@@ skipping 183 matching lines @@
 inline int StylePropertySet::findPropertyIndex(T property) const
 {
     if (m_isMutable)
         return toMutableStylePropertySet(this)->findPropertyIndex(property);
     return toImmutableStylePropertySet(this)->findPropertyIndex(property);
 }
 
 } // namespace blink
 
 #endif // StylePropertySet_h