Remove SetWrapperReferenceTo and SetWrapperReferenceFrom

third_party/WebKit/Source/core/dom/DatasetDOMStringMap.h

 /*
  * Copyright (C) 2010 Apple 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 29 matching lines @@
   }
 
   void getNames(Vector<String>&) override;
   String item(const String& name) override;
   bool contains(const String& name) override;
   void setItem(const String& name,
                const String& value,
                ExceptionState&) override;
   bool deleteItem(const String& name) override;
 
-  Element* element() override { return m_element; }
-
   DECLARE_VIRTUAL_TRACE();
 
  private:
   explicit DatasetDOMStringMap(Element* element) : m_element(element) {}
 
   Member<Element> m_element;
 };
 
 }  // namespace blink
 
 #endif  // DatasetDOMStringMap_h