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

tests/compiler/dart2js_native/runtimetype_test.dart

Index: tests/compiler/dart2js_native/runtimetype_test.dart
diff --git a/tests/compiler/dart2js_native/runtimetype_test.dart b/tests/compiler/dart2js_native/runtimetype_test.dart
index dc8d7a4d5b9e34a7d5733ccffdbdc91e4cf234c6..460dfd082d74fe9503be5e23bc19de73e82a490c 100644
--- a/tests/compiler/dart2js_native/runtimetype_test.dart
+++ b/tests/compiler/dart2js_native/runtimetype_test.dart
@@ -3,15 +3,18 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import "package:expect/expect.dart";
+import "dart:_js_helper";
 import 'dart:_foreign_helper' show JS;
 
 // Test to see runtimeType works on native classes and does not use the native
 // constructor name.
 
-class A native "TAGX" {
+@Native("TAGX")
+class A {
 }
 
-class B extends A native "TAGY" {
+@Native("TAGY")
+class B extends A {
 }
 
 makeA() native;