Comment out frequently flaky PrivateStore test

chrome/browser/chromeos/login/kiosk_browsertest.cc

 // Copyright (c) 2013 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 <memory>
 #include <vector>
 
 #include "ash/desktop_background/desktop_background_controller.h"
 #include "ash/desktop_background/desktop_background_controller_observer.h"
 #include "ash/shell.h"
@@ skipping 2279 matching lines @@
   Profile* app_profile = ProfileManager::GetPrimaryUserProfile();
   ASSERT_TRUE(app_profile);
   EXPECT_FALSE(
       SigninManagerFactory::GetForProfile(app_profile)->IsAuthenticated());
 
   // Terminate the app.
   window->GetBaseWindow()->Close();
   content::RunAllPendingInMessageLoop();
 }
 
-IN_PROC_BROWSER_TEST_F(KioskEnterpriseTest, PrivateStore) {
+#if defined(OS_CHROMEOS)
+#define MAYBE_PrivateStore DISABLED_PrivateStore
+#else
+#define MAYBE_PrivateStore PrivateStore
+#endif
+IN_PROC_BROWSER_TEST_F(KioskEnterpriseTest, MAYBE_PrivateStore) {
   set_test_app_id(kTestEnterpriseKioskApp);
 
   const char kPrivateStoreUpdate[] = "/private_store_update";
   net::EmbeddedTestServer private_server;
   ASSERT_TRUE(private_server.Start());
 
   // |private_server| serves crx from test data dir.
   base::FilePath test_data_dir;
   PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir);
   private_server.ServeFilesFromDirectory(test_data_dir);
@@ skipping 99 matching lines @@
   content::WindowedNotificationObserver(
       chrome::NOTIFICATION_KIOSK_AUTOLAUNCH_WARNING_VISIBLE,
       content::NotificationService::AllSources()).Wait();
 
   // Wait for the wallpaper to load.
   WaitForWallpaper();
   EXPECT_TRUE(wallpaper_loaded());
 }
 
 }  // namespace chromeos