Remove support for attribute event listeners.

client/dom/generated/src/interface/HTMLBodyElement.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // WARNING: Do not edit - generated code.
 
 interface HTMLBodyElement extends HTMLElement {
 
   String get aLink();
 
   void set aLink(String value);
 
   String get background();
 
   void set background(String value);
 
   String get bgColor();
 
   void set bgColor(String value);
 
   String get link();
 
   void set link(String value);
 
-  EventListener get onbeforeunload();
-
-  void set onbeforeunload(EventListener value);
-
-  EventListener get onblur();
-
-  void set onblur(EventListener value);
-
-  EventListener get onerror();
-
-  void set onerror(EventListener value);
-
-  EventListener get onfocus();
-
-  void set onfocus(EventListener value);
-
-  EventListener get onhashchange();
-
-  void set onhashchange(EventListener value);
-
-  EventListener get onload();
-
-  void set onload(EventListener value);
-
-  EventListener get onmessage();
-
-  void set onmessage(EventListener value);
-
-  EventListener get onoffline();
-
-  void set onoffline(EventListener value);
-
-  EventListener get ononline();
-
-  void set ononline(EventListener value);
-
-  EventListener get onorientationchange();
-
-  void set onorientationchange(EventListener value);
-
-  EventListener get onpopstate();
-
-  void set onpopstate(EventListener value);
-
-  EventListener get onresize();
-
-  void set onresize(EventListener value);
-
-  EventListener get onstorage();
-
-  void set onstorage(EventListener value);
-
-  EventListener get onunload();
-
-  void set onunload(EventListener value);
-
   String get text();
 
   void set text(String value);
 
   String get vLink();
 
   void set vLink(String value);
 }