Revert "Remove Expect from core library."

tests/standalone/io/secure_session_resume_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.
 //
 // This test tests TLS session resume, by making multiple client connections
 // on the same port to the same server, with a delay of 200 ms between them.
 // The unmodified secure_server_test creates all sessions simultaneously,
 // which means that no handshake completes and caches its keys in the session
 // cache in time for other connections to use it.
 //
 // Session resume is currently disabled - see issue
 // https://code.google.com/p/dart/issues/detail?id=7230
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
-import "package:expect/expect.dart";
 import "dart:async";
 import "dart:io";
 import "dart:isolate";
 
 const SERVER_ADDRESS = "127.0.0.1";
 const HOST_NAME = "localhost";
 const CERTIFICATE = "localhost_cert";
 Future<SecureServerSocket> startServer() {
   return SecureServerSocket.bind(SERVER_ADDRESS,
                                  0,
@@ skipping 37 matching lines @@
   startServer()
       .then((server) => Future.wait(
           ['able', 'baker', 'charlie', 'dozen', 'elapse']
           .map((name) {
             delay += delay_between_connections;
             return new Future.delayed(delay, () => server)
             .then((server) => testClient(server, name));
           })))
       .then((servers) => servers.first.close());
 }