CrOS: Do not allow notifications to be added during shutdown.

chrome/browser/notifications/notification_test_util.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_
 #define CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 52 matching lines @@
                                ProfileID profile_id) const override;
   bool CancelById(const std::string& delegate_id,
                   ProfileID profile_id) override;
   std::set<std::string> GetAllIdsByProfileAndSourceOrigin(
       ProfileID profile_id,
       const GURL& source) override;
   std::set<std::string> GetAllIdsByProfile(ProfileID profile_id) override;
   bool CancelAllBySourceOrigin(const GURL& source_origin) override;
   bool CancelAllByProfile(ProfileID profile_id) override;
   void CancelAll() override;
+  void StartShutdown() override;
 
  private:
   using NotificationPair = std::pair<Notification, ProfileID>;
   std::vector<NotificationPair> notifications_;
 
   base::Closure notification_added_callback_;
 
+  bool is_shutdown_started_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(StubNotificationUIManager);
 };
 
 // Helper class that has to be created in the stack to check if the fullscreen
 // setting of a browser is in the desired state.
 class FullscreenStateWaiter {
  public:
   FullscreenStateWaiter(Browser* browser, bool desired_state);
 
   void Wait();
 
  private:
   Browser* browser_;
   bool desired_state_;
 
   DISALLOW_COPY_AND_ASSIGN(FullscreenStateWaiter);
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_NOTIFICATION_TEST_UTIL_H_