Add @Native(...) annotation for native class names.

tests/compiler/dart2js_native/call_on_native_class_test.dart

Index: tests/compiler/dart2js_native/call_on_native_class_test.dart
diff --git a/tests/compiler/dart2js_native/call_on_native_class_test.dart b/tests/compiler/dart2js_native/call_on_native_class_test.dart
index 3b07cf6be0192d8daa41c4c37c37d0909127cd67..51429821bf3d2bfd756c5911feb3c0e0fe549b97 100644
--- a/tests/compiler/dart2js_native/call_on_native_class_test.dart
+++ b/tests/compiler/dart2js_native/call_on_native_class_test.dart
@@ -2,10 +2,13 @@
 // 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.
 
-class A native '*A' {
+import 'dart:_js_helper';
+
+@Native('*A')
+class A {
 }
 
-class B extends A{
+class B extends A {
   call() => 42;
 }