Make DocumentFragment implement Element.

client/html/src/ElementWrappingImplementation.dart

 // 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.
 
 // TODO(jacobr): use Lists.dart to remove some of the duplicated functionality.
 class _ChildrenElementList implements ElementList {
   // Raw Element.
   final _element;
   final _childElements;
 
@@ skipping 584 matching lines @@
   }
 
   void focus() {
     _ptr.focus();
   }
 
   ClientRect getBoundingClientRect() {
     return LevelDom.wrapClientRect(_ptr.getBoundingClientRect());
   }
 
-  ClientRectList getClientRects() {
-    return LevelDom.wrapClientRectList(_ptr.getClientRects());
+  List<ClientRect> getClientRects() {
+    var rects = LevelDom.wrapClientRectList(_ptr.getClientRects());
+    var out = new List(rects.length);
+    for (var i = 0; i < rects.length; i++) {
+      out.add(rects.item(i));
+    }
+    return out;
   }
 
   Element insertAdjacentElement([String where = null, Element element = null]) {
     return LevelDom.wrapElement(_ptr.insertAdjacentElement(where, LevelDom.unwrap(element)));
   }
 
   void insertAdjacentHTML([String position_OR_where = null, String text = null]) {
     _ptr.insertAdjacentHTML(position_OR_where, text);
   }
 
@@ skipping 27 matching lines @@
     return _ptr.webkitMatchesSelector(selectors);
   }
 
   ElementEvents get on() {
     if (_on === null) {
       _on = new ElementEventsImplementation._wrap(_ptr);
     }
     return _on;
   }
 }