Change new List(n) to return fixed length list.

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;
 
 // TODO(jacobr): use _Lists.dart to remove some of the duplicated
 // functionality.
 class _ChildrenElementList implements List {
   // Raw Element.
   final Element _element;
   final HtmlCollection _childElements;
 
   _ChildrenElementList._wrap(Element element)
     : _childElements = element.$dom_children,
       _element = element;
 
-  List<Element> toList() {
-    final output = new List<Element>.fixedLength(_childElements.length);
+  List<Element> toList({ bool growable: false }) {
+    final output;
+    if (growable) {
+      output = <Element>[];
+      output.length = _childElements.length;
+    } else {
+      output = new List<Element>(_childElements.length);
+    }
     for (int i = 0, len = _childElements.length; i < len; i++) {
       output[i] = _childElements[i];
     }
     return output;
   }
 
   Set<Element> toSet() {
     final output = new Set<Element>();
     for (int i = 0, len = _childElements.length; i < len; i++) {
       output.add(_childElements[i]);
@@ skipping 275 matching lines @@
 
   bool any(bool f(Element element)) {
     for(Element element in this) {
       if (f(element)) {
         return true;
       }
     };
     return false;
   }
 
-  List<Element> toList() => new List<Element>.from(this);
+  List<Element> toList({ bool growable: false }) =>
+      new List<Element>.from(this, growable: growable);
   Set<Element> toSet() => new Set<Element>.from(this);
 
   Iterable<Element> take(int n) {
     return IterableMixinWorkaround.takeList(this, n);
   }
 
   Iterable<Element> takeWhile(bool test(Element value)) {
     return IterableMixinWorkaround.takeWhile(this, test);
   }
 
@@ skipping 782 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');
 }