Remove deprecated Expect from the libraries.

tests/standalone/io/regress_9194_test.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 "package:expect/expect.dart";
 import 'dart:io';
 
 void main() {
   HttpServer.bind('127.0.0.1', 0).then((server) {
       server.listen((request) {
         request.response
             ..reasonPhrase = ''
             ..close();
       });
 
       HttpClient client = new HttpClient();
       client.get("127.0.0.1", server.port, "/")
           .then((HttpClientRequest request) {
             return request.close();
           })
           .then((HttpClientResponse response) {
             Expect.equals("", response.reasonPhrase);
             server.close();
             client.close();
           });
     });
 }