Make subclasses of AbstractContextTest asynchronous.

pkg/analysis_server/test/services/refactoring/rename_label_test.dart

 // Copyright (c) 2014, 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.
 
 library test.services.refactoring.rename_label;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'abstract_rename.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(RenameLabelTest);
   });
 }
 
 @reflectiveTest
 class RenameLabelTest extends RenameRefactoringTest {
-  test_checkNewName_LocalVariableElement() {
-    indexTestUnit('''
+  test_checkNewName_LocalVariableElement() async {
+    await indexTestUnit('''
 main() {
 test:
   while (true) {
     break test;
   }
 }
 ''');
     createRenameRefactoringAtString('test:');
     // null
     refactoring.newName = null;
     assertRefactoringStatus(
         refactoring.checkNewName(), RefactoringProblemSeverity.FATAL,
         expectedMessage: "Label name must not be null.");
     // empty
     refactoring.newName = '';
     assertRefactoringStatus(
         refactoring.checkNewName(), RefactoringProblemSeverity.FATAL,
         expectedMessage: "Label name must not be empty.");
     // OK
     refactoring.newName = 'newName';
     assertRefactoringStatusOK(refactoring.checkNewName());
   }
 
-  test_createChange() {
-    indexTestUnit('''
+  test_createChange() async {
+    await indexTestUnit('''
 main() {
 test:
   while (true) {
     break test;
   }
 }
 ''');
     // configure refactoring
     createRenameRefactoringAtString('test:');
     expect(refactoring.refactoringName, 'Rename Label');
     expect(refactoring.elementKindName, 'label');
     refactoring.newName = 'newName';
     // validate change
     return assertSuccessfulRefactoring('''
 main() {
 newName:
   while (true) {
     break newName;
   }
 }
 ''');
   }
 
-  test_oldName() {
-    indexTestUnit('''
+  test_oldName() async {
+    await indexTestUnit('''
 main() {
 test:
   while (true) {
     break test;
   }
 }
 ''');
     // configure refactoring
     createRenameRefactoringAtString('test:');
     // old name
     expect(refactoring.oldName, 'test');
   }
 }