Revert "Remove Expect from core library."

tests/language/parse_types_test.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.
 // Dart test for testing parsing of "standard" types.
 
-import "package:expect/expect.dart";
-
 class ParseTypesTest {
   static bool callBool1() {
     return true;
   }
 
   static bool callBool2() {
     return false;
   }
 
   static int callInt() {
@@ skipping 13 matching lines @@
     Expect.equals(false, ParseTypesTest.callBool2());
     Expect.equals(2, ParseTypesTest.callInt());
     Expect.equals("Hey", ParseTypesTest.callString());
     Expect.equals(4.0, ParseTypesTest.callDouble());
   }
 }
 
 main() {
   ParseTypesTest.testMain();
 }