Remove the CSSOM.

sky/engine/core/editing/EditingStyle.cpp

 /*
  * Copyright (C) 2007, 2008, 2009 Apple Computer, Inc.
  * Copyright (C) 2010, 2011 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
@@ skipping 13 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/editing/EditingStyle.h"
 
 #include "gen/sky/core/HTMLNames.h"
 #include "sky/engine/bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "sky/engine/core/css/CSSComputedStyleDeclaration.h"
 #include "sky/engine/core/css/CSSPropertyMetadata.h"
-#include "sky/engine/core/css/CSSRuleList.h"
-#include "sky/engine/core/css/CSSStyleRule.h"
 #include "sky/engine/core/css/CSSValueList.h"
 #include "sky/engine/core/css/CSSValuePool.h"
 #include "sky/engine/core/css/FontSize.h"
 #include "sky/engine/core/css/StylePropertySet.h"
 #include "sky/engine/core/css/StyleRule.h"
 #include "sky/engine/core/css/parser/BisonCSSParser.h"
 #include "sky/engine/core/css/resolver/StyleResolver.h"
 #include "sky/engine/core/dom/Document.h"
 #include "sky/engine/core/dom/Element.h"
 #include "sky/engine/core/dom/Node.h"
@@ skipping 534 matching lines @@
 {
     for (Node* ancestor = node; ancestor; ancestor = ancestor->parentNode()) {
         RefPtr<CSSComputedStyleDeclaration> ancestorStyle = CSSComputedStyleDeclaration::create(ancestor);
         if (!hasTransparentBackgroundColor(ancestorStyle.get()))
             return ancestorStyle->getPropertyCSSValue(CSSPropertyBackgroundColor);
     }
     return nullptr;
 }
 
 }