Support DOMString[] and regenerate from IDL

client/dom/generated/src/interface/WebSocket.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 WebSocket extends EventTarget {
 
   static final int CLOSED = 3;
 
   static final int CLOSING = 2;
 
   static final int CONNECTING = 0;
 
   static final int OPEN = 1;
 
   String get URL();
 
   String get binaryType();
 
   void set binaryType(String value);
 
   int get bufferedAmount();
 
+  String get extensions();
+
   EventListener get onclose();
 
   void set onclose(EventListener value);
 
   EventListener get onerror();
 
   void set onerror(EventListener value);
 
   EventListener get onmessage();
 
@@ skipping 10 matching lines @@
   void addEventListener(String type, EventListener listener, [bool useCapture]);
 
   void close([int code, String reason]);
 
   bool dispatchEvent(Event evt);
 
   void removeEventListener(String type, EventListener listener, [bool useCapture]);
 
   bool send(String data);
 }