Move CSSOM classes to using MutableStylePropertySet over StylePropertySet.

Source/core/inspector/InspectorCSSAgent.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 1437 matching lines @@
     }
 
     return result;
 }
 
 PassRefPtr<TypeBuilder::CSS::CSSStyle> InspectorCSSAgent::buildObjectForAttributesStyle(Element* element)
 {
     if (!element->isStyledElement())
         return 0;
 
-    const StylePropertySet* attributeStyle = static_cast<StyledElement*>(element)->presentationAttributeStyle();
+    // FIXME: Ugliness below.
+    StylePropertySet* attributeStyle = const_cast<StylePropertySet*>(static_cast<StyledElement*>(element)->presentationAttributeStyle());
     if (!attributeStyle)
         return 0;
 
-    RefPtr<InspectorStyle> inspectorStyle = InspectorStyle::create(InspectorCSSId(), const_cast<StylePropertySet*>(attributeStyle)->ensureCSSStyleDeclaration(), 0);
+    ASSERT(attributeStyle->isMutable());
+    MutableStylePropertySet* mutableAttributeStyle = static_cast<MutableStylePropertySet*>(attributeStyle);
+
+    RefPtr<InspectorStyle> inspectorStyle = InspectorStyle::create(InspectorCSSId(), mutableAttributeStyle->ensureCSSStyleDeclaration(), 0);
     return inspectorStyle->buildObjectForStyle();
 }
 
 PassRefPtr<TypeBuilder::Array<TypeBuilder::CSS::Region> > InspectorCSSAgent::buildArrayForRegions(ErrorString* errorString, PassRefPtr<NodeList> regionList, int documentNodeId)
 {
     RefPtr<TypeBuilder::Array<TypeBuilder::CSS::Region> > regions = TypeBuilder::Array<TypeBuilder::CSS::Region>::create();
 
     for (unsigned i = 0; i < regionList->length(); ++i) {
         TypeBuilder::CSS::Region::RegionOverset::Enum regionOverset;
 
@@ skipping 95 matching lines @@
             documentsToChange.add(element->ownerDocument());
     }
 
     m_nodeIdToForcedPseudoState.clear();
     for (HashSet<Document*>::iterator it = documentsToChange.begin(), end = documentsToChange.end(); it != end; ++it)
         (*it)->styleResolverChanged(RecalcStyleImmediately);
 }
 
 } // namespace WebCore