Remove deprecated Expect from the libraries.

tests/language/getter_setter_order_test.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.
 
 // Test for the evaluation order of getters and setters.
 
+import 'package:expect/expect.dart';
+
 var trace;
 
 class X {
   get b {
     trace.add('get b');
     return new X();
   }
 
   set c (value) {
     trace.add('set c');
@@ skipping 66 matching lines @@
 
   trace = [];
   x.b.c = x.d[42] *= '$x'.hashCode;
   Expect.listEquals(
       ['get b', 'get d', 'index', 'toString', 'indexSet', 'set c'], trace);
 
   trace = [];
   x.b.c = ++x.d.c;
   Expect.listEquals(['get b', 'get d', 'get c', 'set c', 'set c'], trace);
 }