Rename/tweak some StylePropertySet/CSSStyleDeclaration copying functions.

Source/core/css/PropertySetCSSStyleDeclaration.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Research In Motion Limited. 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 284 matching lines @@
         clonedValue = internalValue->cloneForCSSOM();
     return clonedValue.get();
 }
 
 StyleSheetContents* PropertySetCSSStyleDeclaration::contextStyleSheet() const
 { 
     CSSStyleSheet* cssStyleSheet = parentStyleSheet();
     return cssStyleSheet ? cssStyleSheet->contents() : 0;
 }
 
-PassRefPtr<StylePropertySet> PropertySetCSSStyleDeclaration::copy() const
+PassRefPtr<MutableStylePropertySet> PropertySetCSSStyleDeclaration::copyProperties() const
 {
-    return m_propertySet->copy();
+    return m_propertySet->mutableCopy();
 }
 
 bool PropertySetCSSStyleDeclaration::cssPropertyMatches(CSSPropertyID propertyID, const CSSValue* propertyValue) const
 {
     return m_propertySet->propertyMatches(propertyID, propertyValue);
 }
     
 StyleRuleCSSStyleDeclaration::StyleRuleCSSStyleDeclaration(StylePropertySet* propertySet, CSSRule* parentRule)
     : PropertySetCSSStyleDeclaration(propertySet)
     , m_refCount(1)
@@ skipping 76 matching lines @@
     m_parentElement->invalidateStyleAttribute();
     StyleAttributeMutationScope(this).didInvalidateStyleAttr();
 }
 
 CSSStyleSheet* InlineCSSStyleDeclaration::parentStyleSheet() const
 {
     return m_parentElement ? m_parentElement->document()->elementSheet() : 0;
 }
 
 } // namespace WebCore