Revert of evaluating clipboard event target acording to w3c specification

third_party/WebKit/Source/core/html/HTMLButtonElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. 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.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef HTMLButtonElement_h
 #define HTMLButtonElement_h
 
-#include "core/CoreExport.h"
 #include "core/html/HTMLFormControlElement.h"
 
 namespace blink {
 
-class CORE_EXPORT HTMLButtonElement final : public HTMLFormControlElement {
+class HTMLButtonElement final : public HTMLFormControlElement {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   static HTMLButtonElement* create(Document&);
 
   void setType(const AtomicString&);
 
   const AtomicString& value() const;
 
   bool willRespondToMouseClickEvents() override;
@@ skipping 35 matching lines @@
   bool isOptionalFormControl() const override { return true; }
   bool recalcWillValidate() const override;
 
   Type m_type;
   bool m_isActivatedSubmit;
 };
 
 }  // namespace blink
 
 #endif  // HTMLButtonElement_h