Menu in StocksApp should animate out

sky/examples/stocks-fn/lib/stock_app.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'package:sky/framework/components/action_bar.dart';
 import 'package:sky/framework/components/drawer.dart';
 import 'package:sky/framework/components/drawer_header.dart';
 import 'package:sky/framework/components/floating_action_button.dart';
 import 'package:sky/framework/components/icon.dart';
 import 'package:sky/framework/components/icon_button.dart';
@@ skipping 127 matching lines @@
   Node build() {
     List<Node> overlays = [];
 
     if (_menuController != null) {
       overlays.add(new EventTarget(
         new StockMenu(controller: _menuController),
         onGestureTap: (_) {
           // TODO(abarth): We should close the menu when you tap away from the
           // menu rather than when you tap on the menu.
           setState(() {
-            _menuController.close();
-            _menuController = null;
+            _menuController.close().then((_) {
+              setState(() {
+                _menuController = null;
+              });
+            });
           });
         }
       ));
     }
 
     return new Scaffold(
       header: _isSearching ? buildSearchBar() : buildActionBar(),
       content: new Stocklist(stocks: _stocks, query: _searchQuery),
       fab: new FloatingActionButton(
         content: new Icon(type: 'content/add_white', size: 24), level: 3),
       drawer: buildDrawer(),
       overlays: overlays
     );
   }
 }