Remove more oilpan.

sky/engine/core/dom/shadow/ShadowRoot.h

 /*
  * Copyright (C) 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 27 matching lines @@
 class Document;
 class ElementShadow;
 class ExceptionState;
 class HTMLShadowElement;
 class InsertionPoint;
 class ShadowRootRareData;
 class StyleSheetList;
 
 class ShadowRoot final : public DocumentFragment, public TreeScope, public DoublyLinkedListNode<ShadowRoot> {
     DEFINE_WRAPPERTYPEINFO();
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ShadowRoot);
     friend class WTF::DoublyLinkedListNode<ShadowRoot>;
 public:
 
     static PassRefPtr<ShadowRoot> create(Document& document)
     {
         return adoptRef(new ShadowRoot(document));
     }
 
     void recalcStyle(StyleRecalcChange);
 
@@ skipping 84 matching lines @@
 {
     return adjustedFocusedElement();
 }
 
 DEFINE_NODE_TYPE_CASTS(ShadowRoot, isShadowRoot());
 DEFINE_TYPE_CASTS(ShadowRoot, TreeScope, treeScope, treeScope->rootNode().isShadowRoot(), treeScope.rootNode().isShadowRoot());
 
 } // namespace blink
 
 #endif // ShadowRoot_h