Use 'field' syntax in dart:dom interfaces.

client/dom/generated/src/interface/StorageEvent.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 StorageEvent extends Event {
 
-  String get key();
+  final String key;
 
-  String get newValue();
+  final String newValue;
 
-  String get oldValue();
+  final String oldValue;
 
-  Storage get storageArea();
+  final Storage storageArea;
 
-  String get url();
+  final String url;
 
   void initStorageEvent(String typeArg, bool canBubbleArg, bool cancelableArg, String keyArg, String oldValueArg, String newValueArg, String urlArg, Storage storageAreaArg);
 }