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

tools/dom/templates/html/impl/impl_Element.darttemplate

 // 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 $LIBRARYNAME;
 
 class _ChildrenElementList extends ListBase<Element> {
   // Raw Element.
   final Element _element;
   final HtmlCollection _childElements;
@@ skipping 40 matching lines @@
 
     for (Element element in iterable) {
       _element.append(element);
     }
   }
 
   void sort([int compare(Element a, Element b)]) {
     throw new UnsupportedError('Cannot sort element lists');
   }
 
-  void shuffle() {
+  void shuffle([Random random]) {
     throw new UnsupportedError('Cannot shuffle element lists');
   }
 
   void removeWhere(bool test(Element element)) {
     _filter(test, false);
   }
 
   void retainWhere(bool test(Element element)) {
     _filter(test, true);
   }
@@ skipping 201 matching lines @@
   }
 
   void set length(int newLength) {
     throw new UnsupportedError('Cannot modify list');
   }
 
   void sort([Comparator<Element> compare]) {
     throw new UnsupportedError('Cannot sort list');
   }
 
-  void shuffle() {
+  void shuffle([Random random]) {
     throw new UnsupportedError('Cannot shuffle list');
   }
 
   Element get first => _nodeList.first;
 
   Element get last => _nodeList.last;
 
   Element get single => _nodeList.single;
 
   CssClassSet get classes => new _MultiElementCssClassSet(_elementList);
@@ skipping 1113 matching lines @@
   const ScrollAlignment._internal(this._value);
   toString() => 'ScrollAlignment.$_value';
 
   /// Attempt to align the element to the top of the scrollable area.
   static const TOP = const ScrollAlignment._internal('TOP');
   /// Attempt to center the element in the scrollable area.
   static const CENTER = const ScrollAlignment._internal('CENTER');
   /// Attempt to align the element to the bottom of the scrollable area.
   static const BOTTOM = const ScrollAlignment._internal('BOTTOM');
 }