Split layout2.dart into several files

sky/sdk/lib/framework/components2/input.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 '../editing/editable_string.dart';
 import '../editing/editable_text.dart';
 import '../editing/keyboard.dart';
 import '../fn2.dart';
-import '../layout2.dart';
 import '../theme/colors.dart';
 import '../theme/typography.dart' as typography;
 import 'dart:sky' as sky;
 
 typedef void ValueChanged(value);
 
 class Input extends Component {
   static final Style _style = new Style('''
     transform: translateX(0);
     margin: 8px;
@@ skipping 67 matching lines @@
       new FlexContainer(
         direction: FlexDirection.Column,
         style: _style,
         inlineStyle: focused ? _focusedInlineStyle : null,
         children: children
       ),
       onPointerDown: (sky.Event e) => keyboard.showByRequest()
     );
   }
 }