Make subclasses of AbstractContextTest asynchronous.

pkg/analysis_server/test/services/refactoring/abstract_refactoring.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;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart'
     show
@@ skipping 142 matching lines @@
   }
 
   /**
    * Completes with a fully resolved unit that contains the [element].
    */
   Future<CompilationUnit> getResolvedUnitWithElement(Element element) async {
     return element.context
         .resolveCompilationUnit(element.source, element.library);
   }
 
-  void indexTestUnit(String code) {
-    resolveTestUnit(code);
+  Future<Null> indexTestUnit(String code) async {
+    await resolveTestUnit(code);
     index.indexUnit(testUnit);
   }
 
-  void indexUnit(String file, String code) {
+  Future<Null> indexUnit(String file, String code) async {
     Source source = addSource(file, code);
-    CompilationUnit unit = resolveLibraryUnit(source);
+    CompilationUnit unit = await resolveLibraryUnit(source);
     index.indexUnit(unit);
   }
 
   void setUp() {
     super.setUp();
     index = createMemoryIndex();
     searchEngine = new SearchEngineImpl(index);
   }
 }