Fix random test failures for issue_27238_test

runtime/observatory/tests/service/issue_27238_test.dart

 // Copyright (c) 2015, 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=--error_on_bad_type --error_on_bad_override  --verbose_debug
 
 import 'package:observatory/service_io.dart';
 import 'service_test_common.dart';
 import 'dart:async';
 import 'test_helper.dart';
 import 'dart:developer';
@@ skipping 15 matching lines @@
   print('foo1'); // LINE_D.
   print('foo2'); // LINE_E.
 }
 
 var tests = [
   hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_A),
   smartNext,
   hasStoppedAtBreakpoint,
   smartNext,
+  hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_B),
   smartNext,
   hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_C),
   smartNext,
   hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_D),
   resumeIsolate,
 ];
 
 main(args) => runIsolateTests(args, tests, testeeConcurrent: testMain);