Add redirect method to HttpResponse

sdk/lib/io/http_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;
 
 class _HttpIncoming extends Stream<List<int>> {
   final int _transferLength;
   final Completer _dataCompleter = new Completer();
   Stream<List<int>> _stream;
@@ skipping 690 matching lines @@
     if (_cookies == null) _cookies = new List<Cookie>();
     return _cookies;
   }
 
   String get reasonPhrase => _findReasonPhrase(statusCode);
   void set reasonPhrase(String reasonPhrase) {
     if (_headersWritten) throw new StateError("Header already sent");
     _reasonPhrase = reasonPhrase;
   }
 
+  Future redirect(Uri location, {int status: HttpStatus.MOVED_TEMPORARILY}) {
+    if (_headersWritten) throw new StateError("Header already sent");
+    statusCode = status;
+    headers.set("Location", location.toString());
+    return close();
+  }
+
   Future<Socket> detachSocket() {
     if (_headersWritten) throw new StateError("Headers already sent");
     deadline = null;  // Be sure to stop any deadline.
     var future = _httpRequest._httpConnection.detachSocket();
     _writeHeaders(drainRequest: false).then((_) => close());
     // Close connection so the socket is 'free'.
     close();
     done.catchError((_) {
       // Catch any error on done, as they automatically will be
       // propagated to the websocket.
@@ skipping 1180 matching lines @@
                                        int backlog,
                                        String certificate_name,
                                        bool requestClientCertificate) {
     return SecureServerSocket.bind(
         address,
         port,
         certificate_name,
         backlog: backlog,
         requestClientCertificate: requestClientCertificate)
         .then((socket) {
-          return new _HttpServer._(socket, true);
+            return new _HttpServer._(socket, true);
         });
   }
 
   _HttpServer._(this._serverSocket, this._closeServer) {
     _controller = new StreamController<HttpRequest>(sync: true,
                                                     onCancel: close);
   }
 
   _HttpServer.listenOn(ServerSocket this._serverSocket)
       : _closeServer = false {
@@ skipping 502 matching lines @@
   final Uri location;
 }
 
 String _getHttpVersion() {
   var version = Platform.version;
   // Only include major and minor version numbers.
   int index = version.indexOf('.', version.indexOf('.') + 1);
   version = version.substring(0, index);
   return 'Dart/$version (dart:io)';
 }