Removed DARTIUM codegen for IDLS (sdk/lib/dartium)

tools/dom/templates/html/impl/impl_MessageEvent.darttemplate

 // Copyright (c) 2013, 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.
 
 part of $LIBRARYNAME;
 
 $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
   factory $CLASSNAME(String type,
       {bool canBubble: false, bool cancelable: false, Object data,
       String origin, String lastEventId,
       Window source, List<MessagePort> messagePorts}) {
     if (source == null) {
       source = window;
     }
-$if DART2JS
     if (!Device.isIE) { // TODO: This if check should be removed once IE
       // implements the constructor.
       return JS('MessageEvent', 'new MessageEvent(#, {bubbles: #, cancelable: #, data: #, origin: #, lastEventId: #, source: #, ports: #})',
           type, canBubble, cancelable, data, origin, lastEventId, source,
           messagePorts);
     }
-$endif
     MessageEvent event = document._createEvent("MessageEvent");
     event._initMessageEvent(type, canBubble, cancelable, data, origin,
         lastEventId, source, messagePorts);
     return event;
   }
 
-$if DARTIUM
   // TODO(alanknight): This really should be generated by the
   // _OutputConversion in the systemnative.py script, but that doesn't
   // use those conversions right now, so do this as a one-off.
-  @DomName('MessageEvent.data')
-  @DocsEditable()
-  dynamic get data => convertNativeToDart_SerializedScriptValue(
-      _blink.BlinkMessageEvent.instance.data_Getter_(this));
-
-$else
-  // TODO(alanknight): This really should be generated by the
-  // _OutputConversion in the systemnative.py script, but that doesn't
-  // use those conversions right now, so do this as a one-off.
   @DomName('MessageEvent.data')
   @DocsEditable()
   dynamic get data => convertNativeToDart_SerializedScriptValue(this._get_data);
 
   @JSName('data')
   @DomName('MessageEvent.data')
   @DocsEditable()
   @annotation_Creates_SerializedScriptValue
   @annotation_Returns_SerializedScriptValue
   final dynamic _get_data;
 
-$endif
-
 $!MEMBERS
 }