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

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

 // Copyright (c) 2016, 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;
 
 // TODO(alanknight): Provide a nicer constructor that uses named parameters
 // rather than an initialization map.
 $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 
-$if DARTIUM
   // TODO(alanknight): This really should be generated by the
   // _OutputConversion in the systemnative.py script, but that doesn't
   // use those conversions right now, so do this as a one-off.
-  @DomName('ServiceWorkerMessageEvent.data')
-  @DocsEditable()
-  dynamic get data => convertNativeToDart_SerializedScriptValue(
-      _blink.BlinkMessageEvent.instance.data_Getter_(this));
-$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('ServiceWorkerMessageEvent.data')
   @DocsEditable()
   dynamic get data => convertNativeToDart_SerializedScriptValue(this._get_data);
 
   @JSName('data')
   @DomName('ServiceWorkerMessageEvent.data')
   @DocsEditable()
   @annotation_Creates_SerializedScriptValue
   @annotation_Returns_SerializedScriptValue
   final dynamic _get_data;
-$endif
 
 $!MEMBERS
 }