Revert "Parts must start with 'part of'" and "Attempt to fix VM build"

dart/samples/ui_lib/touch/Scrollbar.dart

-part of touch;
-
 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Implementation of a scrollbar for the custom scrolling behavior
  * defined in [:Scroller:].
  */
 class Scrollbar implements ScrollListener {
   /**
@@ skipping 332 matching lines @@
     style.setProperty(cssPos, '${pos}px', '');
     if (_cachedSize[cssSize] != size) {
       _cachedSize[cssSize] = size;
       style.setProperty(cssSize, '${size}px', '');
     }
     if (element.parent == null) {
       _frame.nodes.add(element);
     }
   }
 }