Fixing issues from IDL upgrade

pkg/custom_element/lib/custom_element.dart

 // Copyright (c) 2013, 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.
 
 /**
  * Custom DOM elements.
  *
  * This library provides access to the Polymer project's
  * [Custom Elements]
  * (http://www.polymer-project.org/platform/custom-elements.html)
@@ skipping 425 matching lines @@
   Node append(Node e) => host.append(e);
 
   void appendText(String text) => host.appendText(text);
 
   void appendHtml(String html) => host.appendHtml(html);
 
   String get regionOverset => host.regionOverset;
 
   List<Range> getRegionFlowRanges() => host.getRegionFlowRanges();
 
+  void animate(List<Map> keyframes, [num duration]) =>
+      host.animate(keyframes, duration);
+
   // TODO(jmesserly): rename "created" to "onCreated".
   void onCreated() => created();
 
   Stream<Event> get onAbort => host.onAbort;
   Stream<Event> get onBeforeCopy => host.onBeforeCopy;
   Stream<Event> get onBeforeCut => host.onBeforeCut;
   Stream<Event> get onBeforePaste => host.onBeforePaste;
   Stream<Event> get onBlur => host.onBlur;
   Stream<Event> get onChange => host.onChange;
   Stream<MouseEvent> get onClick => host.onClick;
@@ skipping 38 matching lines @@
   Stream<TouchEvent> get onTouchLeave => host.onTouchLeave;
   Stream<TouchEvent> get onTouchMove => host.onTouchMove;
   Stream<TouchEvent> get onTouchStart => host.onTouchStart;
   Stream<TransitionEvent> get onTransitionEnd => host.onTransitionEnd;
 
   // TODO(sigmund): do the normal forwarding when dartbug.com/7919 is fixed.
   Stream<WheelEvent> get onMouseWheel {
     throw new UnsupportedError('onMouseWheel is not supported');
   }
 }