Relax vmservice isolate tests.

tests/standalone/vmservice/isolate_list_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.
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 //
 // Test:
 //   *) Connect to VM Service and obtain list of running isolates.
 
 library isolate_list_test;
 
 import 'test_helper.dart';
 import 'package:expect/expect.dart';
 
 
 class IsolateListTest extends VmServiceRequestHelper {
   IsolateListTest(port) : super('http://127.0.0.1:$port/isolates');
 
   onRequestCompleted(Map reply) {
-    // The reply is an IsolateList.
-    Expect.equals('IsolateList', reply['type']);
-    // There is 1 running isolate.
-    Expect.equals(1, reply['members'].length);
-    // It's id is 7116.
-    Expect.equals(7116, reply['members'][0]['id']);
-    // It's this isolate.
-    Expect.isTrue(
-        reply['members'][0]['name'].startsWith('isolate_list_script.dart'));
+    IsolateListTester tester = new IsolateListTester(reply);
+    tester.checkIsolateCount(1);
+    tester.checkIsolateNameContains('isolate_list_script.dart');
   }
 }
 
 
 main() {
   var process = new TestLauncher('isolate_list_script.dart');
   process.launch().then((port) {
     var test = new IsolateListTest(port);
     test.makeRequest().then((_) {
       process.requestExit();
     });
   });
 }