Updating dwc for breaking changes that will be part of the next sdk

lib/web_components.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 exposes the types in [watcher], [safe_html], [templating] and
  * the [WebComponent] base class. See this article for more information about
  * this library: <http://www.dartlang.org/articles/dart-web-components/>.
  */
 library web_components;
@@ skipping 313 matching lines @@
   }
 
   Map<String, String> get dataAttributes => _element.dataAttributes;
   set dataAttributes(Map<String, String> value) {
     _element.dataAttributes = value;
   }
 
   Map<String, String> getNamespacedAttributes(String namespace) =>
       _element.getNamespacedAttributes(namespace);
 
-  Future<CSSStyleDeclaration> get computedStyle => _element.computedStyle;
+  Future<CssStyleDeclaration> get computedStyle => _element.computedStyle;
 
-  Future<CSSStyleDeclaration> getComputedStyle(String pseudoElement)
+  Future<CssStyleDeclaration> getComputedStyle(String pseudoElement)
     => _element.getComputedStyle(pseudoElement);
 
   Element clone(bool deep) => _element.clone(deep);
 
   Element get parent => _element.parent;
 
   ElementEvents get on => _element.on;
 
   String get contentEditable => _element.contentEditable;
 
@@ skipping 48 matching lines @@
   }
 
   Map<String, String> get dataset => _element.dataset;
 
   Element get nextElementSibling => _element.nextElementSibling;
 
   Element get offsetParent => _element.offsetParent;
 
   Element get previousElementSibling => _element.previousElementSibling;
 
-  CSSStyleDeclaration get style => _element.style;
+  CssStyleDeclaration get style => _element.style;
 
   String get tagName => _element.tagName;
 
   void blur() { _element.blur(); }
 
   void focus() { _element.focus(); }
 
   void scrollByLines(int lines) {
     _element.scrollByLines(lines);
   }
@@ skipping 17 matching lines @@
   }
 
   void webkitRequestFullscreen() { _element.webkitRequestFullscreen(); }
 
   void webkitRequestPointerLock() { _element.webkitRequestPointerLock(); }
 
   Element query(String selectors) => _element.query(selectors);
 
   List<Element> queryAll(String selectors) => _element.queryAll(selectors);
 
-  HTMLCollection get $dom_children => _element.$dom_children;
+  HtmlCollection get $dom_children => _element.$dom_children;
 
   int get $dom_childElementCount => _element.$dom_childElementCount;
 
   String get $dom_className => _element.$dom_className;
   set $dom_className(String value) { _element.$dom_className = value; }
 
   int get clientHeight => _element.clientHeight;
 
   int get clientLeft => _element.clientLeft;
 
   int get clientTop => _element.clientTop;
 
   int get clientWidth => _element.clientWidth;
 
-  int get childElementCount => _element.childElementCount;
-
-  Element get firstElementChild => _element.firstElementChild;
-
-  Element get lastElementChild => _element.lastElementChild;
-
   Element get $dom_firstElementChild => _element.$dom_firstElementChild;
 
   Element get $dom_lastElementChild => _element.$dom_lastElementChild;
 
   int get offsetHeight => _element.offsetHeight;
 
   int get offsetLeft => _element.offsetLeft;
 
   int get offsetTop => _element.offsetTop;
 
@@ skipping 98 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;