Ensure that privates are private.

extensions/renderer/module_system_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/renderer/module_system.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 487 matching lines @@
   scoped_ptr<ModuleSystemTestEnvironment> other_env = CreateEnvironment();
   gin::ModuleRegistry::From(env()->context()->v8_context())
       ->AddBuiltinModule(
           env()->isolate(), "natives",
           other_env->module_system()->NewInstance());
   other_env->ShutdownModuleSystem();
   env()->module_system()->Require("test");
   RunResolvedPromises();
 }
 
+TEST_F(ModuleSystemTest, TestPrivatesIsPrivate) {
+  ModuleSystem::NativesEnabledScope natives_enabled_scope(
+      env()->module_system());
+  env()->RegisterModule(
+      "test",
+      "var v = privates({});"
+      "requireNative('assert').AssertFalse(v instanceof Object);");
+  env()->module_system()->Require("test");
+}
+
 }  // namespace extensions