Make ElementList return ElementLists.

client/html/src/NodeWrappingImplementation.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.
 
 class _ChildrenNodeList implements NodeList {
   // Raw node.
   final _node;
   final _childNodes;
 
   _ChildrenNodeList._wrap(var node)
@@ skipping 119 matching lines @@
     }
     return last;
   }
 
   Node last() {
     return LevelDom.wrapNode(_node.lastChild);
   }
 }
 
 // TODO(nweiz): when all implementations we target have the same name for the
-// coreimpl implementation of List<Node>, extend that rather than wrapping.
-class _NodeList implements NodeList {
-  List<Node> _list;
+// coreimpl implementation of List<E>, extend that rather than wrapping.
+class _ListWrapper<E> implements List<E> {
+  List<E> _list;
 
-  _NodeList(List<Node> this._list);
+  _ListWrapper(List<E> this._list);
 
-  Iterator<Node> iterator() => _list.iterator();
+  Iterator<E> iterator() => _list.iterator();
 
-  void forEach(void f(Node element)) => _list.forEach(f);
+  void forEach(void f(E element)) => _list.forEach(f);
 
-  Collection map(f(Node element)) => _list.map(f);
+  Collection map(f(E element)) => _list.map(f);
 
-  NodeList filter(bool f(Node element)) => new _NodeList(_list.filter(f));
+  List<E> filter(bool f(E element)) => _list.filter(f);
 
-  bool every(bool f(Node element)) => _list.every(f);
+  bool every(bool f(E element)) => _list.every(f);
 
-  bool some(bool f(Node element)) => _list.some(f);
+  bool some(bool f(E element)) => _list.some(f);
 
   bool isEmpty() => _list.isEmpty();
 
   int get length() => _list.length;
 
-  Node operator [](int index) => _list[index];
+  E operator [](int index) => _list[index];
 
-  void operator []=(int index, Node value) { _list[index] = value; }
+  void operator []=(int index, E value) { _list[index] = value; }
 
   void set length(int newLength) { _list.length = newLength; }
 
-  void add(Node value) => _list.add(value);
+  void add(E value) => _list.add(value);
 
-  void addLast(Node value) => _list.addLast(value);
+  void addLast(E value) => _list.addLast(value);
 
-  void addAll(Collection<Node> collection) => _list.addAll(collection);
+  void addAll(Collection<E> collection) => _list.addAll(collection);
 
-  void sort(int compare(Node a, Node b)) => _list.sort(compare);
+  void sort(int compare(E a, E b)) => _list.sort(compare);
 
-  int indexOf(Node element, [int start = 0]) => _list.indexOf(element, start);
+  int indexOf(E element, [int start = 0]) => _list.indexOf(element, start);
 
-  int lastIndexOf(Node element, [int start = 0]) =>
+  int lastIndexOf(E element, [int start = 0]) =>
     _list.lastIndexOf(element, start);
 
   void clear() => _list.clear();
 
-  Node removeLast() => _list.removeLast();
+  E removeLast() => _list.removeLast();
 
-  Node last() => _list.last();
+  E last() => _list.last();
 
-  NodeList getRange(int start, int length) =>
-    new _NodeList(_list.getRange(start, length));
+  List<E> getRange(int start, int length) => _list.getRange(start, length);
 
-  void setRange(int start, int length, List<Node> from, [int startFrom = 0]) =>
+  void setRange(int start, int length, List<E> from, [int startFrom = 0]) =>
     _list.setRange(start, length, from, startFrom);
 
   void removeRange(int start, int length) => _list.removeRange(start, length);
 
-  void insertRange(int start, int length, [Node initialValue = null]) =>
+  void insertRange(int start, int length, [E initialValue = null]) =>
     _list.insertRange(start, length, initialValue);
 
-  Node get first() => _list[0];
+  E get first() => _list[0];
+}
+
+class _NodeList extends _ListWrapper<Node> implements NodeList {
+  _NodeList(List<Node> list) : super(list);
+
+  NodeList filter(bool f(Node element)) => new _NodeList(super.filter(f));
+
+  NodeList getRange(int start, int length) =>
+    new _NodeList(super.getRange(start, length));
 }
 
 class NodeWrappingImplementation extends EventTargetWrappingImplementation implements Node {
   NodeList _nodes;
 
   NodeWrappingImplementation._wrap(ptr) : super._wrap(ptr);
 
   void set nodes(Collection<Node> value) {
     // Copy list first since we don't want liveness during iteration.
     List copy = new List.from(value);
@@ skipping 52 matching lines @@
   // array.
   Node insertBefore(Node newChild, Node refChild) {
     return LevelDom.wrapNode(_ptr.insertBefore(
         LevelDom.unwrap(newChild), LevelDom.unwrap(refChild)));
   }
 
   Node clone(bool deep) {
     return LevelDom.wrapNode(_ptr.cloneNode(deep));
   }
 }