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

dart/samples/ui_lib/base/Size.dart

-part of base;
-
 // 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.
 
 /**
  * A utility class for representing two-dimensional sizes.
  */
 class Size {
   num width;
   num height;
@@ skipping 118 matching lines @@
   }
 
   /**
    * Returns a nice string representing size.
    * Returns in the form (50 x 73).
    */
   String toString() {
     return "(${width} x ${height})";
   }
 }