Remove Expect from core library.

tests/corelib/apply2_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.
 
+import "package:expect/expect.dart";
+
 apply(Function function, ArgumentDescriptor args) {
   return Function.apply(
       function, args.positionalArguments, args.namedArguments);
 }
 
 class ArgumentDescriptor {
   final List positionalArguments;
   final Map<String, dynamic> namedArguments;
 
   ArgumentDescriptor(this.positionalArguments, this.namedArguments);
@@ skipping 62 matching lines @@
       apply(c6, new ArgumentDescriptor([], {'a': 3, 'b': 4})));
   Expect.equals('c6 4 3',
       apply(c6, new ArgumentDescriptor([], {'b': 3, 'a': 4})));
   Expect.equals('c6 2 3',
       apply(c6, new ArgumentDescriptor([], {'b': 3})));
   throwsNSME(() => apply(c6, new ArgumentDescriptor([1], {'a': 1})));
   throwsNSME(() => apply(c6, new ArgumentDescriptor([1], {})));
   throwsNSME(() =>
       apply(c6, new ArgumentDescriptor([], {'a': 1, 'b': 2, 'c': 3})));
 }