Change "typedef" to "class" in core library and related tests.

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;
 
 /**
  * Mixin that throws on the length changing operations of [List].
  *
  * Intended to mix-in on top of [ListMixin] for fixed-length lists.
@@ skipping 169 matching lines @@
         "Cannot modify an unmodifiable list");
   }
 }
 
 /**
  * Abstract implementation of a fixed-length list.
  *
  * All operations are defined in terms of `length`, `operator[]` and
  * `operator[]=`, which need to be implemented.
  */
-typedef FixedLengthListBase<E> = ListBase<E> with FixedLengthListMixin<E>;
+abstract class FixedLengthListBase<E> =
+    ListBase<E> with FixedLengthListMixin<E>;
 
 /**
  * Abstract implementation of an unmodifiable list.
  *
  * All operations are defined in terms of `length` and `operator[]`,
  * which need to be implemented.
  */
-typedef UnmodifiableListBase<E> = ListBase<E> with UnmodifiableListMixin<E>;
+abstract class UnmodifiableListBase<E> =
+    ListBase<E> with UnmodifiableListMixin<E>;
 
 class _ListIndicesIterable extends ListIterable<int> {
   List _backedList;
 
   _ListIndicesIterable(this._backedList);
 
   int get length => _backedList.length;
   int elementAt(int index) {
     if (index < 0 || index >= length) {
       throw new RangeError.range(index, 0, length);
@@ skipping 50 matching lines @@
 }
 
 class ReversedListIterable<E> extends ListIterable<E> {
   Iterable<E> _source;
   ReversedListIterable(this._source);
 
   int get length => _source.length;
 
   E elementAt(int index) => _source.elementAt(_source.length - 1 - index);
 }