add initState, rename animated_container

sky/sdk/example/stocks/lib/stock_settings.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/widgets/basic.dart';
 import 'package:sky/widgets/checkbox.dart';
 import 'package:sky/widgets/switch.dart';
 import 'package:sky/widgets/flat_button.dart';
 import 'package:sky/widgets/dialog.dart';
 import 'package:sky/widgets/icon_button.dart';
@@ skipping 60 matching lines @@
     if (updater != null)
       updater(
         optimism: optimism,
         backup: backup
       );
   }
 
   Widget buildToolBar() {
     return new ToolBar(
       left: new IconButton(
-        icon: 'navigation/arrow_back_white',
+        icon: 'navigation/arrow_back',
         onPressed: navigator.pop),
       center: new Text('Settings')
     );
   }
 
   Widget buildSettingsPane() {
     // TODO(ianh): Once we have the gesture API hooked up, fix https://github.com/domokit/mojo/issues/281
     // (whereby tapping the widgets below causes both the widget and the menu item to fire their callbacks)
     return new Material(
       type: MaterialType.canvas,
@@ skipping 44 matching lines @@
               _handleOptimismChanged(true);
               navigator.pop();
             }
           ),
         ]
       ));
     }
     return new Stack(layers);
   }
 }