Fixing error event type of Workers.

sdk/lib/html/dart2js/html_dart2js.dart

 /// The Dart HTML library.
 library dart.dom.html;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev';
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:isolate';
 import 'dart:json' as json;
@@ skipping 57 matching lines @@
 // 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.
 
 
 @DocsEditable
 @DomName('AbstractWorker')
 class AbstractWorker extends EventTarget native "AbstractWorker" {
 
   @DomName('AbstractWorker.errorEvent')
   @DocsEditable
-  static const EventStreamProvider<Event> errorEvent = const EventStreamProvider<Event>('error');
+  static const EventStreamProvider<ErrorEvent> errorEvent = const EventStreamProvider<ErrorEvent>('error');
 
   @JSName('addEventListener')
   @DomName('AbstractWorker.addEventListener')
   @DocsEditable
   void $dom_addEventListener(String type, EventListener listener, [bool useCapture]) native;
 
   @DomName('AbstractWorker.dispatchEvent')
   @DocsEditable
   bool dispatchEvent(Event evt) native;
 
   @JSName('removeEventListener')
   @DomName('AbstractWorker.removeEventListener')
   @DocsEditable
   void $dom_removeEventListener(String type, EventListener listener, [bool useCapture]) native;
 
   @DomName('AbstractWorker.onerror')
   @DocsEditable
-  Stream<Event> get onError => errorEvent.forTarget(this);
+  Stream<ErrorEvent> get onError => errorEvent.forTarget(this);
 }
 // Copyright (c) 2012, 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.
 
 
 @DocsEditable
 @DomName('HTMLAnchorElement')
 class AnchorElement extends Element native "HTMLAnchorElement" {
 
@@ skipping 29485 matching lines @@
       _position = nextPosition;
       return true;
     }
     _current = null;
     _position = _array.length;
     return false;
   }
 
   T get current => _current;
 }