Update dart2js_foreign suite as we now validate annotations.

dart/tests/compiler/dart2js_foreign/native_null_closure_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 'native_metadata.dart';
+
 typedef void MyFunctionType();
 
-@native("*A")
+@Native("*A")
 class A {
   @native setClosure(MyFunctionType f);
   @native check(MyFunctionType f);
   @native invoke();
 }
 
 @native makeA() { return new A(); }
 
-@native("""
+@Native("""
 function A() {}
 A.prototype.setClosure = function(f) { this.f = f; };
 A.prototype.check = function(f) { return this.f === f; };
 A.prototype.invoke = function() { return this.f(); };
 makeA = function(){return new A;};
 """)
 void setup();
 
 
 main() {
   setup();
   A a = makeA();
   a.setClosure(null);
   Expect.isTrue(a.check(null));
   bool caughtException = false;
   try {
     a.invoke();
   } on Exception catch (e) {
     caughtException = true;
   }
   Expect.isTrue(caughtException);
 }