Fix gesture events in fn2

sky/examples/stocks2/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/components2/tool_bar.dart';
 import 'package:sky/framework/components2/drawer.dart';
 // import 'package:sky/framework/components2/drawer_header.dart';
 // import 'package:sky/framework/components2/floating_action_button.dart';
 // import 'package:sky/framework/components2/icon.dart';
 import 'package:sky/framework/components2/icon_button.dart';
@@ skipping 146 matching lines @@
   //         icon: 'action/help',
   //         children: [new Text('Help & Feedback')])
   //    ]
     );
   }
 
   UINode buildToolBar() {
     return new ToolBar(
         left: new IconButton(
           icon: 'navigation/menu_white',
-          onGestureTap: (_) => _drawerController.toggle),
+          onGestureTap: _drawerController.toggle),
         center: new Text('Stocks'),
         right: [
           new IconButton(
             icon: 'action/search_white',
             onGestureTap: _handleSearchBegin),
           new IconButton(
             icon: 'navigation/more_vert_white',
             onGestureTap: _handleMenuShow)
         ],
         backgroundColor: colors.Purple[500]
@@ skipping 39 matching lines @@
     ];
     addMenuToOverlays(overlays);
     return new StackContainer(children: overlays);
   }
 }
 
 void main() {
   print("starting stocks app!");
   new StocksApp();
 }