Address observatory analysis issues.

runtime/observatory/tests/service/async_star_step_out_test.dart

 // Copyright (c) 2017, 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 --async_debugger
 
 import 'dart:developer';
-import 'package:observatory/models.dart' as M;
-import 'package:observatory/service_io.dart';
-import 'package:unittest/unittest.dart';
+
 import 'service_test_common.dart';
 import 'test_helper.dart';
 
-const LINE_A = 24;
-const LINE_B = 25;
-const LINE_C = 29;
-const LINE_D = 32;
-const LINE_E = 39;
-const LINE_F = 40;
-const LINE_G = 41;
-const LINE_H = 30;
-const LINE_I = 34;
+const LINE_A = 22;
+const LINE_B = 23;
+const LINE_C = 27;
+const LINE_D = 30;
+const LINE_E = 37;
+const LINE_F = 38;
+const LINE_G = 39;
+const LINE_H = 28;
+const LINE_I = 32;
 
 foobar() async* {
   yield 1; // LINE_A.
   yield 2; // LINE_B.
 }
 
 helper() async {
   print('helper'); // LINE_C.
-  await for (var i in foobar()) { // LINE_H.
+  await for (var i in foobar()) /* LINE_H */ {
     debugger();
     print('loop'); // LINE_D.
   }
   return null; // LINE_I.
 }
 
 testMain() {
   debugger();
   print('mmmmm'); // LINE_E.
   helper(); // LINE_F.
@@ skipping 40 matching lines @@
   stoppedAtLine(LINE_H), // await for.
   stepInto,
   hasStoppedAtBreakpoint,
   stepOut, // step out of generator.
   hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_I), // return null.
 ];
 
 main(args) =>
     runIsolateTestsSynchronous(args, tests, testeeConcurrent: testMain);