Add a SafeHttpServer shim to work around issue 9140.

pkg/http/test/utils.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.
 
 library test_utils;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:json' as json;
 import 'dart:uri';
 
 import 'package:unittest/unittest.dart';
 import '../lib/src/byte_stream.dart';
 import '../lib/http.dart' as http;
 import '../lib/src/utils.dart';
+import 'safe_http_server.dart';
 
 /// The current server instance.
 HttpServer _server;
 
 /// The URL for the current server instance.
 Uri get serverUrl => Uri.parse('http://localhost:${_server.port}');
 
 /// A dummy URL for constructing requests that won't be sent.
 Uri get dummyUrl => Uri.parse('http://dartlang.org/');
 
 /// Starts a new HTTP server.
 Future startServer() {
-  return HttpServer.bind("127.0.0.1", 0).then((s) {
+  return SafeHttpServer.bind("127.0.0.1", 0).then((s) {
     _server = s;
     s.listen((request) {
       var path = request.uri.path;
       var response = request.response;
 
       if (path == '/error') {
         response.statusCode = 400;
         response.contentLength = 0;
         response.close();
         return;
@@ skipping 158 matching lines @@
 const isSocketIOException = const _SocketIOException();
 
 /// A matcher for functions that throw SocketIOException.
 const Matcher throwsSocketIOException =
     const Throws(isSocketIOException);
 
 class _SocketIOException extends TypeMatcher {
   const _SocketIOException() : super("SocketIOException");
   bool matches(item, MatchState matchState) => item is SocketIOException;
 }