Update or delete language tests using obsolete interfaces or default factory

tests/language/factory3_negative_test.dart

Index: tests/language/factory3_negative_test.dart
===================================================================
--- tests/language/factory3_negative_test.dart	(revision 15648)
+++ tests/language/factory3_negative_test.dart	(working copy)
@@ -1,16 +1,16 @@
-// 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.
 
 // Test compile time error for factories with parameterized types.
 
-interface Link<T> default LinkFactory {
+abstract class Link<T> default LinkFactory {
   Link.create();
 }
 
 class A<T> { }
 
-// Compile time error: should be LinkFactory<T> to match interface above
+// Compile time error: should be LinkFactory<T> to match abstract class above
 class LinkFactory extends A<int> {
   factory Link.create() {
     return null;