Move id attribute to parent Element interface

Source/core/html/HTMLElement.idl

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * 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.
  */
 
 [
     CustomToV8
 ] interface HTMLElement : Element {
-             // iht.com relies on id returning the empty string when no id is present.
-             // Other browsers do this as well. So we don't convert null to JS null.
-             [Reflect] attribute DOMString id;
              [Reflect] attribute DOMString title;
              [Reflect] attribute DOMString lang;
              attribute boolean             translate;
              [Reflect] attribute DOMString dir;
 
              attribute long              tabIndex;
              attribute boolean           draggable;
              [Reflect] attribute DOMString webkitdropzone;
              [Reflect] attribute boolean hidden;
              [Reflect] attribute DOMString accessKey;
@@ skipping 14 matching lines @@
     [EnabledAtRuntime=imeAPI] InputMethodContext getInputContext();
 
              [TreatNullAs=NullString, SetterRaisesException] attribute DOMString contentEditable;
     readonly attribute boolean isContentEditable;
 
              attribute boolean spellcheck;
 
     void click();
 };