Omnibus Observatory UI fixes:

runtime/observatory/tests/observatory_ui/heap_snapshot/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 'dart:async';
 import 'package:unittest/unittest.dart';
 import 'package:observatory/models.dart' as M;
 import 'package:observatory/src/elements/containers/virtual_tree.dart';
 import 'package:observatory/src/elements/heap_snapshot.dart';
 import '../mocks.dart';
 
 main() {
   HeapSnapshotElement.tag.ensureRegistration();
 
   final tTag = VirtualTreeElement.tag.name;
 
   const vm = const VMMock();
   const isolate = const IsolateRefMock();
   final events = new EventRepositoryMock();
   final notifs = new NotificationRepositoryMock();
   final snapshots = new HeapSnapshotRepositoryMock();
-  final instances = new InstanceRepositoryMock();
+  final objects = new ObjectRepositoryMock();
   test('instantiation', () {
     final e = new HeapSnapshotElement(
-        vm, isolate, events, notifs, snapshots, instances);
+        vm, isolate, events, notifs, snapshots, objects);
     expect(e, isNotNull, reason: 'element correctly created');
   });
   test('elements created', () async {
     final controller =
         new StreamController<M.HeapSnapshotLoadingProgressEvent>.broadcast();
     final snapshots =
         new HeapSnapshotRepositoryMock(getter: (M.IsolateRef i, bool gc) {
       expect(i, equals(isolate));
       expect(gc, isFalse);
       return controller.stream;
     });
     final e = new HeapSnapshotElement(
-        vm, isolate, events, notifs, snapshots, instances);
+        vm, isolate, events, notifs, snapshots, objects);
     document.body.append(e);
     await e.onRendered.first;
     expect(e.children.length, isNonZero, reason: 'has elements');
     expect(e.querySelectorAll(tTag).length, isZero);
     controller.add(const HeapSnapshotLoadingProgressEventMock(
         progress: const HeapSnapshotLoadingProgressMock(
             status: M.HeapSnapshotLoadingStatus.fetching)));
     await e.onRendered.first;
     expect(e.querySelectorAll(tTag).length, isZero);
     controller.add(const HeapSnapshotLoadingProgressEventMock(
         progress: const HeapSnapshotLoadingProgressMock(
             status: M.HeapSnapshotLoadingStatus.loading)));
     controller.add(new HeapSnapshotLoadingProgressEventMock(
         progress: new HeapSnapshotLoadingProgressMock(
             status: M.HeapSnapshotLoadingStatus.loaded,
             snapshot: new HeapSnapshotMock(timestamp: new DateTime.now()))));
     controller.close();
     await e.onRendered.first;
     expect(e.querySelectorAll(tTag).length, equals(1));
     e.remove();
     await e.onRendered.first;
     expect(e.children.length, isZero, reason: 'is empty');
   });
 }