Split layout2.dart into several files

sky/sdk/lib/framework/components2/ink_well.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 '../fn2.dart';
-import '../layout2.dart';
 import 'dart:collection';
 import 'dart:sky' as sky;
 import 'ink_splash.dart';
 import 'scrollable.dart';
 
 class InkWell extends Component implements ScrollClient {
   static final Style _containmentStyleHack = new Style('''
     align-items: center;
     transform: translateX(0);''');
 
@@ skipping 93 matching lines @@
   void _splashDone(SplashController splash) {
     if (_splashes == null)
       return;
     setState(() {
       _splashes.remove(splash);
       if (_splashes.length == 0)
         _splashes = null;
     });
   }
 }