Make List.shuffle take an optional Random object to use.

sdk/lib/core/list.dart

 // Copyright (c) 2012, 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.
 
 part of dart.core;
 
 /**
  * An indexable collection of objects with a length.
  *
  * Subclasses of this class implement different kinds of lists.
@@ skipping 166 matching lines @@
    *
    *     List<int> nums = [13, 2, -11];
    *     nums.sort();
          nums.join(', '); // '-11, 2, 13'
    */
   void sort([int compare(E a, E b)]);
 
   /**
    * Shuffles the elements of this list randomly.
    */
-  void shuffle();
+  void shuffle([Random random]);
 
   /**
    * Returns the first index of [element] in this list.
    *
    * Searches the list from index [start] to the end of the list.
    * The first time an object [:o:] is encountered so that [:o == element:],
    * the index of [:o:] is returned.
    *
    *     List<String> notes = ['do', 're', 'mi', 're'];
    *     notes.indexOf('re');    // 1
@@ skipping 231 matching lines @@
    * as values. The `Map.keys` [Iterable] iterates the indices of this list
    * in numerical order.
    *
    *     List<String> words = ['fee', 'fi', 'fo', 'fum'];
    *     Map<int, String> map = words.asMap();
    *     map[0] + map[1];   // 'feefi';
    *     map.keys.toList(); // [0, 1, 2, 3]
    */
   Map<int, E> asMap();
 }