Revert "Use Timer and not AnimationFrame during Observatory UI tests"

runtime/observatory/tests/observatory_ui/nav/vm_menu/element_test.dart

Index: runtime/observatory/tests/observatory_ui/nav/vm_menu/element_test.dart
diff --git a/runtime/observatory/tests/observatory_ui/nav/vm_menu/element_test.dart b/runtime/observatory/tests/observatory_ui/nav/vm_menu/element_test.dart
index 6c018d2983cf7fd1f393de731dabc6a4631538a9..b0539ff46979a3fbf79798c12d6c0b8bac481d39 100644
--- a/runtime/observatory/tests/observatory_ui/nav/vm_menu/element_test.dart
+++ b/runtime/observatory/tests/observatory_ui/nav/vm_menu/element_test.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 import 'package:unittest/unittest.dart';
 import 'package:observatory/mocks.dart';
 import 'package:observatory/models.dart' as M;
-import 'package:observatory/src/elements/helpers/rendering_queue.dart';
 import 'package:observatory/src/elements/nav/menu.dart';
 import 'package:observatory/src/elements/nav/menu_item.dart';
 import 'package:observatory/src/elements/nav/vm_menu.dart';
@@ -17,9 +16,6 @@ main(){
   final mTag = NavMenuElement.tag.name;
   final miTag = NavMenuItemElement.tag.name;
 
-  final TimedRenderingBarrier barrier = new TimedRenderingBarrier();
-  final RenderingQueue queue = new RenderingQueue.fromBarrier(barrier);
-
   StreamController<M.VMUpdateEvent> updatesController;
   final TargetMock target = new TargetMock(name: 'target-name');
   final VMMock vm1 = const VMMock(name: 'vm-name-1',
@@ -48,7 +44,7 @@ main(){
   });
   test('elements created after attachment', () async {
     final NavVMMenuElement e = new NavVMMenuElement(vm1,
-        updatesController.stream, queue: queue);
+        updatesController.stream);
     document.body.append(e);
     await e.onRendered.first;
     expect(e.shadowRoot.children.length, isNonZero, reason: 'has elements');
@@ -59,7 +55,7 @@ main(){
   group('updates', () {
     test('are correctly listen', () async {
       final NavVMMenuElement e = new NavVMMenuElement(vm1,
-          updatesController.stream, queue: queue);
+          updatesController.stream);
       expect(updatesController.hasListener, isFalse);
       document.body.append(e);
       await e.onRendered.first;
@@ -70,7 +66,7 @@ main(){
     });
     test('have effects', () async {
       final NavVMMenuElement e = new NavVMMenuElement(vm1,
-          updatesController.stream, queue: queue);
+          updatesController.stream);
       document.body.append(e);
       await e.onRendered.first;
       expect((e.shadowRoot.querySelector(mTag) as NavMenuElement).label,
@@ -84,7 +80,6 @@ main(){
       expect(e.shadowRoot.querySelectorAll(miTag).length,
           equals(vm2.isolates.length));
       e.remove();
-      await e.onRendered.first;
     });
   });
 }