Make hasNext a getter instead of a method.

lib/html/src/_ListIterators.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.
 
 // Iterator for arrays with fixed size.
 class _FixedSizeListIterator<T> extends _VariableSizeListIterator<T> {
   _FixedSizeListIterator(List<T> array)
       : super(array),
         _length = array.length;
 
-  bool hasNext() => _length > _pos;
+  bool get hasNext => _length > _pos;
 
   final int _length;  // Cache array length for faster access.
 }
 
 // Iterator for arrays with variable size.
 class _VariableSizeListIterator<T> implements Iterator<T> {
   _VariableSizeListIterator(List<T> array)
       : _array = array,
         _pos = 0;
 
-  bool hasNext() => _array.length > _pos;
+  bool get hasNext => _array.length > _pos;
 
   T next() {
-    if (!hasNext()) {
+    if (!hasNext) {
       throw const NoMoreElementsException();
     }
     return _array[_pos++];
   }
 
   final List<T> _array;
   int _pos;
 }