Allow additional headers for WebSocket connect

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 383 matching lines @@
       // Send the upgrade response.
       response
           ..statusCode = HttpStatus.SWITCHING_PROTOCOLS
           ..headers.add(HttpHeaders.CONNECTION, "Upgrade")
           ..headers.add(HttpHeaders.UPGRADE, "websocket");
       String key = request.headers.value("Sec-WebSocket-Key");
       _SHA1 sha1 = new _SHA1();
       sha1.add("$key$_webSocketGUID".codeUnits);
       String accept = _CryptoUtils.bytesToBase64(sha1.close());
       response.headers.add("Sec-WebSocket-Accept", accept);
-      if (protocol != null && protocol.isNotEmpty) {
+      if (protocol != null) {
         response.headers.add("Sec-WebSocket-Protocol", protocol);
       }
       response.headers.contentLength = 0;
       return response.detachSocket()
           .then((socket) => new _WebSocketImpl._fromSocket(
                 socket, protocol, true));
     }
 
     var protocols = request.headers['Sec-WebSocket-Protocol'];
     if (protocols != null && _protocolSelector != null) {
@@ skipping 347 matching lines @@
   Duration _pingInterval;
   Timer _pingTimer;
   _WebSocketConsumer _consumer;
 
   int _outCloseCode;
   String _outCloseReason;
   Timer _closeTimer;
 
   static final HttpClient _httpClient = new HttpClient();
 
-  static Future<WebSocket> connect(String url, List<String> protocols) {
+  static Future<WebSocket> connect(
+      String url, Iterable<String> protocols, Map<String, dynamic> headers) {
     Uri uri = Uri.parse(url);
     if (uri.scheme != "ws" && uri.scheme != "wss") {
       throw new WebSocketException("Unsupported URL scheme '${uri.scheme}'");
     }
     if (uri.userInfo != "") {
       throw new WebSocketException("Unsupported user info '${uri.userInfo}'");
     }
 
     Random random = new Random();
     // Generate 16 random bytes.
     Uint8List nonceData = new Uint8List(16);
     for (int i = 0; i < 16; i++) {
       nonceData[i] = random.nextInt(256);
     }
     String nonce = _CryptoUtils.bytesToBase64(nonceData);
 
     uri = new Uri(scheme: uri.scheme == "wss" ? "https" : "http",
                   userInfo: uri.userInfo,
                   host: uri.host,
                   port: uri.port,
                   path: uri.path,
                   query: uri.query,
                   fragment: uri.fragment);
     return _httpClient.openUrl("GET", uri)
       .then((request) {
+        if (headers != null) {
+          headers.forEach((field, value) => request.headers.add(field, value));
+        }
         // Setup the initial handshake.
         request.headers
-            ..add(HttpHeaders.CONNECTION, "Upgrade")
+            ..set(HttpHeaders.CONNECTION, "Upgrade")
             ..set(HttpHeaders.UPGRADE, "websocket")
             ..set("Sec-WebSocket-Key", nonce)
             ..set("Cache-Control", "no-cache")
             ..set("Sec-WebSocket-Version", "13");
-        if (protocols.isNotEmpty) {
-          request.headers.add("Sec-WebSocket-Protocol", protocols);
+        if (protocols != null) {
+          request.headers.add("Sec-WebSocket-Protocol", protocols.toList());
         }
         return request.close();
       })
       .then((response) {
         void error(String message) {
           // Flush data.
           response.detachSocket().then((socket) {
             socket.destroy();
           });
           throw new WebSocketException(message);
@@ skipping 191 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));
   }
 }