Add support to specify the source address for socket connect

sdk/lib/_internal/compiler/js_lib/io_patch.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.
 
 import 'dart:_js_helper' show patch;
 
 @patch
 class _Directory {
   @patch
   static _current() {
@@ skipping 360 matching lines @@
                                    int port,
                                    {int backlog: 0,
                                     bool v6Only: false}) {
     throw new UnsupportedError("ServerSocket.bind");
   }
 }
 
 @patch
 class RawSocket {
   @patch
-  static Future<RawSocket> connect(host, int port) {
+  static Future<RawSocket> connect(host, int port, {sourceAddress}) {
     throw new UnsupportedError("RawSocket constructor");
   }
 }
 
 @patch
 class Socket {
   @patch
-  static Future<Socket> connect(host, int port) {
+  static Future<Socket> connect(host, int port, {sourceAddress}) {
     throw new UnsupportedError("Socket constructor");
   }
 }
 
 @patch
 class SecureSocket {
   @patch
   factory SecureSocket._(RawSecureSocket rawSocket) {
     throw new UnsupportedError("SecureSocket constructor");
   }
@@ skipping 128 matching lines @@
   }
 }
 
 @patch
 class _IOService {
   @patch
   static Future _dispatch(int request, List data) {
     throw new UnsupportedError("_IOService._dispatch");
   }
 }