upgrades for version 0.5.16

lib/web_ui.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.
 
 /**
  * This library exports all of the commonly used functions and types for
  * building UI's. It is equivalent to the following imports:
  *
  *     import 'package:web_ui/observe.dart';
  *     import 'package:web_ui/safe_html.dart';
@@ skipping 661 matching lines @@
     }
   }
 
   String get regionOverset => host.regionOverset;
 
   List<Range> getRegionFlowRanges() => host.getRegionFlowRanges();
 
   // TODO(jmesserly): rename "created" to "onCreated".
   void onCreated() => created();
 
-  Node get insertionParent => host.insertionParent;
-
   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;
   Stream<MouseEvent> get onContextMenu => host.onContextMenu;
   Stream<Event> get onCopy => host.onCopy;
   Stream<Event> get onCut => host.onCut;
@@ skipping 66 matching lines @@
 }
 
 /**
  * Set this to true to use native Shadow DOM if it is supported.
  * Note that this will change behavior of [WebComponent] APIs for tree
  * traversal.
  */
 bool useShadowDom = false;
 
 bool get _realShadowRoot => useShadowDom && ShadowRoot.supported;