Rationalize Dart mojo and sky package structure

sky/sdk/lib/framework/components/action_bar.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 '../fn.dart';
 import '../layout.dart';
 import '../theme/view_configuration.dart';
 import 'material.dart';
 
 class ActionBar extends Component {
@@ skipping 27 matching lines @@
       children.addAll(right);
 
     return new Material(
       content: new FlexContainer(
         style: _style,
         children: children,
         direction: FlexDirection.Row),
       level: 2);
   }
 }