Untype 'Socket' a few places, where we try to call a hidden function.

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 733 matching lines @@
 class _WebSocketImpl extends Stream with _ServiceObject implements WebSocket {
   // Use default Map so we keep order.
   static Map<int, _WebSocketImpl> _webSockets = new Map<int, _WebSocketImpl>();
 
   final String protocol;
 
   StreamController _controller;
   StreamSubscription _subscription;
   StreamSink _sink;
 
-  final Socket _socket;
+  final _socket;
   final bool _serverSide;
   int _readyState = WebSocket.CONNECTING;
   bool _writeClosed = false;
   int _closeCode;
   String _closeReason;
   Duration _pingInterval;
   Timer _pingTimer;
   _WebSocketConsumer _consumer;
 
   int _outCloseCode;
@@ skipping 240 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));
   }
 }