Fix typos.

sdk/lib/collection_dev/list.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.
 
 part of dart.collection.dev;
 
 /**
  * Class implementing the read-operations on [List].
  *
  * Implements all read-only operations, except [:operator[]:] and [:length:],
@@ skipping 471 matching lines @@
       newStart = -count;
     } else {
       newStart = _end - count;
       if (_end >= 0 && newStart < 0) {
         return new EmptyList<E>();
       }
     }
     return _createReversedListView(newStart, _end);
   }
 
-  Iterable<E> get iterator => new ReverseListIterator<E>(
+  Iterator<E> get iterator => new ReverseListIterator<E>(
       _list, _absoluteIndex(_start), _absoluteIndex(_end));
 
   List<E> get reversed {
     return new ListView(_list, _start, _end);
   }
 }
 
 /**
  * An [Iterator] over a slice of a list that access elements in reverse order.
  */
 class ReverseListIterator<E> implements Iterator<E> {
   final List<E> _list;
   final int _start;
   final int _originalLength;
   int _index;
   E _current;
 
   ReverseListIterator(List<E> list, int start, int end)
       : _list = list,
         _start = start,
         _index = end,
         _originalLength = list.length;
 
   bool moveNext() {
-    if (list.length != _originalLength) {
+    if (_list.length != _originalLength) {
       throw new ConcurrentModificationError(list);
     }
     if (_index <= _start) return false;
     _index -= 1;
     _current = _list[_index];
     return true;
   }
 
   E get current => _current;
 }