Converted Observatory vm-nav-menu element

runtime/observatory/lib/src/mocks/objects/event.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
 
 part of mocks;
 
+class VMUpdateEventMock implements M.VMUpdateEvent {
+  final M.VMRef vm;
+  const VMUpdateEventMock({this.vm});
+}
+
 class IsolateUpdateEventMock implements M.IsolateUpdateEvent {
   final DateTime timestamp;
   final M.IsolateRef isolate;
   const IsolateUpdateEventMock({this.timestamp, this.isolate});
 }