Revert "Remove Expect from core library."

tests/language/named_parameters_test.dart

 // Copyright (c) 2012, 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.
 // Dart test program for testing named parameters.
 
-import "package:expect/expect.dart";
-
 
 class NamedParametersTest {
 
   static int F00() {
     return 0;
   }
 
   int f11() {
     return 0;
   }
@@ skipping 90 matching lines @@
 main() {
   NamedParametersTest.testMain();
   var i = new I();
   Expect.equals(100, i.mul(10));
   Expect.equals(1000, i.mul(10, 100));
   var c = new C();
   Expect.equals(100, c.mul(10));
   Expect.equals(1000, c.mul(10, 100));
   Expect.equals("Edna sent gladiolas to possums", message());
 }