Remove support for attribute event listeners.

client/dom/generated/src/wrapping/_EventSourceWrappingImplementation.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.
 
 class _EventSourceWrappingImplementation extends DOMWrapperBase implements EventSource {
   _EventSourceWrappingImplementation() : super() {}
 
   static create__EventSourceWrappingImplementation() native {
     return new _EventSourceWrappingImplementation();
   }
 
   String get URL() { return _get_URL(this); }
   static String _get_URL(var _this) native;
 
-  EventListener get onerror() { return _get_onerror(this); }
-  static EventListener _get_onerror(var _this) native;
-
-  void set onerror(EventListener value) { _set_onerror(this, value); }
-  static void _set_onerror(var _this, EventListener value) native;
-
-  EventListener get onmessage() { return _get_onmessage(this); }
-  static EventListener _get_onmessage(var _this) native;
-
-  void set onmessage(EventListener value) { _set_onmessage(this, value); }
-  static void _set_onmessage(var _this, EventListener value) native;
-
-  EventListener get onopen() { return _get_onopen(this); }
-  static EventListener _get_onopen(var _this) native;
-
-  void set onopen(EventListener value) { _set_onopen(this, value); }
-  static void _set_onopen(var _this, EventListener value) native;
-
   int get readyState() { return _get_readyState(this); }
   static int _get_readyState(var _this) native;
 
   void addEventListener(String type, EventListener listener, [bool useCapture = null]) {
     if (useCapture === null) {
       _addEventListener_EventSource(this, type, listener);
       return;
     } else {
       _addEventListener_EventSource_2(this, type, listener, useCapture);
       return;
@@ skipping 20 matching lines @@
     } else {
       _removeEventListener_EventSource_2(this, type, listener, useCapture);
       return;
     }
   }
   static void _removeEventListener_EventSource(receiver, type, listener) native;
   static void _removeEventListener_EventSource_2(receiver, type, listener, useCapture) native;
 
   String get typeName() { return "EventSource"; }
 }