Unflake PlatformNotificationServiceTest.NotificationPermissionLastUsage

chrome/browser/notifications/platform_notification_service_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 "base/strings/utf_string_conversions.h"
+#include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "chrome/browser/notifications/notification_test_util.h"
 #include "chrome/browser/notifications/platform_notification_service_impl.h"
 #include "chrome/test/base/testing_profile.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "content/public/browser/desktop_notification_delegate.h"
 #include "content/public/common/platform_notification_data.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ skipping 179 matching lines @@
   GURL origin("https://chrome.com/");
   base::Time begin_time;
 
   CreateSimplePageNotification();
 
   base::Time after_page_notification =
       profile()->GetHostContentSettingsMap()->GetLastUsage(
           origin, origin, CONTENT_SETTINGS_TYPE_NOTIFICATIONS);
   EXPECT_GT(after_page_notification, begin_time);
 
+  // Ensure that there is at least some time between the two calls.
+  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(1));
+
   service()->DisplayPersistentNotification(profile(),
                                            42 /* sw_registration_id */,
                                            origin,
                                            SkBitmap(),
                                            content::PlatformNotificationData(),
                                            0 /* render_process_id */);
 
   base::Time after_persistent_notification =
       profile()->GetHostContentSettingsMap()->GetLastUsage(
           origin, origin, CONTENT_SETTINGS_TYPE_NOTIFICATIONS);
   EXPECT_GT(after_persistent_notification, after_page_notification);
 }