Removed dynamic Symbol creation and marked Bindable classes

runtime/observatory/lib/src/elements/nav/top_menu_wrapper.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:observatory/app.dart';
 import 'package:observatory/src/elements/helpers/tag.dart';
 import 'package:observatory/src/elements/shims/binding.dart';
 import 'package:observatory/src/elements/nav/top_menu.dart';
 
+@bindable
 class NavTopMenuElementWrapper extends HtmlElement {
-  static final binder = new Binder<NavTopMenuElementWrapper>(
-    const [const Binding('last')]);
+  static const binder = const Binder<NavTopMenuElementWrapper>(const {
+      'last': #last
+    });
 
   static const tag = const Tag<NavTopMenuElementWrapper>('top-nav-menu');
 
   bool _last = false;
   bool get last => _last;
   set last(bool value) {
     _last = value; render();
   }
 
   NavTopMenuElementWrapper.created() : super.created() {
@@ skipping 17 matching lines @@
       new NavTopMenuElement(last: last, queue: ObservatoryApplication.app.queue)
         ..children = [new ContentElement()]
     ];
   }
 
   bool _getBoolAttribute(String name) {
     final String value = getAttribute(name);
     return !(value == null || value == 'false');
   }
 }