Update or delete language tests using obsolete interfaces or default factory

tests/language/class_override_negative_test.dart

Index: tests/language/class_override_negative_test.dart
===================================================================
--- tests/language/class_override_negative_test.dart	(revision 15648)
+++ tests/language/class_override_negative_test.dart	(working copy)
@@ -1,9 +1,9 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
-// 8.1 Methods: It is a compile-time error if an interface method m1 overrides 
-// an interface method m2 and has a different number of required parameters.
+// 8.1 Methods: It is a compile-time error if a method m1 overrides
+// a method m2 and has a different number of required parameters.
 
 class A {
   foo() {}