Fix stepping over await statements

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';
 
-const int LINE_A = 19;
-const int LINE_B = 20;
-const int LINE_C = 21;
+const int LINE_A = 20;
+const int LINE_B = 23;
+const int LINE_C = 24;
+const int LINE_D = 26;
+const int LINE_E = 27;
 
-foo() async { }
+testMain() async {
+  debugger();
+  Future future1 = new Future.value();  // LINE_A.
+  Future future2 = new Future.value();
 
-doAsync(stop) async {
-  if (stop) debugger();
-  await foo(); // Line A.
-  await foo(); // Line B.
-  await foo(); // Line C.
-  return null;
-}
+  await future1;  // LINE_B.
+  await future2;  // LINE_C.
 
-testMain() {
-  // With two runs of doAsync floating around, async step should only cause
-  // us to stop in the run we started in.
-  doAsync(false);
-  doAsync(true);
-}
-
-asyncNext(Isolate isolate) async {
-  print('asyncNext');
-  return asyncStepOver(isolate);
+  print('foo1'); // LINE_D.
+  print('foo2'); // LINE_E.
 }
 
 var tests = [
   hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_A),
-  stepOver, // foo()
-  asyncNext,
+  smartNext,
   hasStoppedAtBreakpoint,
+  smartNext,
   stoppedAtLine(LINE_B),
-  stepOver, // foo()
-  asyncNext,
+  smartNext,
   hasStoppedAtBreakpoint,
   stoppedAtLine(LINE_C),
+  smartNext,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_D),
   resumeIsolate,
 ];
 
 main(args) => runIsolateTests(args, tests, testeeConcurrent: testMain);