Bugfix in dart:io's WebSocketTransformer implementation, correctly test async behaviour of websocke…

dart/sdk/lib/io/websocket_impl.dart

 // 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.
 
 part of dart.io;
 
 const String _webSocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 
 // Matches _WebSocketOpcode.
 class _WebSocketMessageType {
@@ skipping 354 matching lines @@
       new StreamController<WebSocket>(sync: true);
   final Function _protocolSelector;
 
   _WebSocketTransformerImpl(this._protocolSelector);
 
   Stream<WebSocket> bind(Stream<HttpRequest> stream) {
     stream.listen((request) {
         _upgrade(request, _protocolSelector)
             .then((WebSocket webSocket) => _controller.add(webSocket))
             .catchError(_controller.addError);
+    }, onDone: () {
+      _controller.close();
     });
 
     return _controller.stream;
   }
 
   static Future<WebSocket> _upgrade(HttpRequest request, _protocolSelector) {
     var response = request.response;
     if (!_isUpgradeRequest(request)) {
       // Send error response.
       response
@@ skipping 621 matching lines @@
            (code < WebSocketStatus.NORMAL_CLOSURE ||
             code == WebSocketStatus.RESERVED_1004 ||
             code == WebSocketStatus.NO_STATUS_RECEIVED ||
             code == WebSocketStatus.ABNORMAL_CLOSURE ||
             (code > WebSocketStatus.INTERNAL_SERVER_ERROR &&
              code < WebSocketStatus.RESERVED_1015) ||
             (code >= WebSocketStatus.RESERVED_1015 &&
              code < 3000));
   }
 }