Rename/tweak some StylePropertySet/CSSStyleDeclaration copying functions.

Source/core/css/StylePropertySet.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 478 matching lines @@
     for (unsigned i = 0; i < size; ++i) {
         PropertyReference property = propertyAt(i);
         if (style->cssPropertyMatches(property.id(), property.value()))
             propertiesToRemove.append(property.id());
     }    
     // FIXME: This should use mass removal.
     for (unsigned i = 0; i < propertiesToRemove.size(); ++i)
         removeProperty(propertiesToRemove[i]);
 }
 
-PassRefPtr<StylePropertySet> StylePropertySet::copy() const
+PassRefPtr<MutableStylePropertySet> StylePropertySet::mutableCopy() const
 {
     return adoptRef(new MutableStylePropertySet(*this));
 }
 
-PassRefPtr<StylePropertySet> StylePropertySet::copyPropertiesInSet(const Vector<CSSPropertyID>& properties) const
+PassRefPtr<MutableStylePropertySet> StylePropertySet::copyPropertiesInSet(const Vector<CSSPropertyID>& properties) const
 {
     Vector<CSSProperty, 256> list;
     list.reserveInitialCapacity(properties.size());
     for (unsigned i = 0; i < properties.size(); ++i) {
         RefPtr<CSSValue> value = getPropertyCSSValue(properties[i]);
         if (value)
             list.append(CSSProperty(properties[i], value.release(), false));
     }
-    return StylePropertySet::create(list.data(), list.size());
+    return static_pointer_cast<MutableStylePropertySet>(StylePropertySet::create(list.data(), list.size()));
 }
 
 PropertySetCSSStyleDeclaration* StylePropertySet::cssStyleDeclaration()
 {
     if (!m_ownsCSSOMWrapper)
         return 0;
     ASSERT(isMutable());
     return propertySetCSSOMWrapperMap().get(this);
 }
 
@@ skipping 85 matching lines @@
     result.appendLiteral(": ");
     result.append(propertyValue()->cssText());
     if (isImportant())
         result.appendLiteral(" !important");
     result.append(';');
     return result.toString();
 }
 
 
 } // namespace WebCore