Omnibus Observatory UI fixes:

runtime/observatory/tests/observatory_ui/context_view/element_test.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:html';
 import 'package:unittest/unittest.dart';
 import 'package:observatory/src/elements/context_view.dart';
 import 'package:observatory/src/elements/nav/refresh.dart';
 import 'package:observatory/src/elements/object_common.dart';
 import '../mocks.dart';
 
 main() {
   ContextViewElement.tag.ensureRegistration();
 
   final cTag = ObjectCommonElement.tag.name;
   final rTag = NavRefreshElement.tag.name;
 
   const vm = const VMMock();
   const isolate = const IsolateRefMock();
   final events = new EventRepositoryMock();
   final notifs = new NotificationRepositoryMock();
   final context = const ContextMock();
   final contexts = new ContextRepositoryMock();
   final reachableSizes = new ReachableSizeRepositoryMock();
   final retainedSizes = new RetainedSizeRepositoryMock();
   final inbounds = new InboundReferencesRepositoryMock();
   final paths = new RetainingPathRepositoryMock();
-  final instances = new InstanceRepositoryMock();
+  final objects = new ObjectRepositoryMock();
   test('instantiation', () {
     final e = new ContextViewElement(vm, isolate, context, events, notifs,
-        contexts, retainedSizes, reachableSizes, inbounds, paths, instances);
+        contexts, retainedSizes, reachableSizes, inbounds, paths, objects);
     expect(e, isNotNull, reason: 'element correctly created');
     expect(e.isolate, equals(isolate));
     expect(e.context, equals(context));
   });
   test('elements created after attachment', () async {
     final contexts = new ContextRepositoryMock(
         getter: expectAsync((i, id) async {
       expect(i, equals(isolate));
       expect(id, equals(context.id));
       return context;
     }, count: 1));
     final e = new ContextViewElement(vm, isolate, context, events, notifs,
-        contexts, retainedSizes, reachableSizes, inbounds, paths, instances);
+        contexts, retainedSizes, reachableSizes, inbounds, paths, objects);
     document.body.append(e);
     await e.onRendered.first;
     expect(e.children.length, isNonZero, reason: 'has elements');
     expect(e.querySelectorAll(cTag).length, equals(1));
     (e.querySelector(rTag) as NavRefreshElement).refresh();
     await e.onRendered.first;
     e.remove();
     await e.onRendered.first;
     expect(e.children.length, isZero, reason: 'is empty');
   });
 }