Dart: Uses tearDownAll in mojo_apptest.

mojo/dart/packages/mojo_apptest/lib/apptest.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 library mojo_apptest;
 
 import 'dart:async';
 
 import 'package:mojo/application.dart';
 import 'package:mojo/bindings.dart';
@@ skipping 18 matching lines @@
   // call from the shell. We need to first have a valid connection to the shell
   // so that apptests can connect to other applications.
   void initialize(List<String> args, String url) {
     group('dart_apptests', () {
       setUp(testSetUp);
       tearDown(testTearDown);
       for (var testFunction in _testFunctions) {
         testFunction(this, url);
       }
     });
-    // Append a final test to terminate shell connection.
-    // TODO(johnmccutchan): Remove this once package 'test' supports a global
-    // tearDown callback.
-    test('TERMINATE SHELL CONNECTION', () async {
+
+    tearDownAll(() async {
       await close();
       MojoHandle.reportLeakedHandles();
     });
   }
 
   void testSetUp() {}
 
   Future testTearDown() async {
     // Reset any connections between tests.
     await resetConnections();
   }
 }
 
 /// The public interface to apptests.
 ///
 /// In a dart mojo application, [incomingHandle] is `args[0]`. [testFunctions]
 /// is list of [AppTestFunction]. Each function will be passed the application
 /// and url.
 runAppTests(var incomingHandle, List<AppTestFunction> testFunctions) {
   var appHandle = new MojoHandle(incomingHandle);
   var application =
       new _ConnectionToShellApplication.fromHandle(appHandle, testFunctions);
 
   /// [Application]'s [initialize] will be called.
 }