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

chrome/browser/notifications/message_center_notification_manager.cc

 // 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.
 
 #include "chrome/browser/notifications/message_center_notification_manager.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/notifications/extension_welcome_notification.h"
 #include "chrome/browser/notifications/extension_welcome_notification_factory.h"
 #include "chrome/browser/notifications/fullscreen_notification_blocker.h"
 #include "chrome/browser/notifications/message_center_settings_controller.h"
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/notifications/profile_notification.h"
 #include "chrome/browser/notifications/screen_lock_notification_blocker.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/url_constants.h"
@@ skipping 48 matching lines @@
 MessageCenterNotificationManager::~MessageCenterNotificationManager() {
   message_center_->SetNotifierSettingsProvider(nullptr);
   message_center_->RemoveObserver(this);
 
   profile_notifications_.clear();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NotificationUIManager
 
 void MessageCenterNotificationManager::Add(const Notification& notification,

[sky, 2017/03/28 22:00:34]

Would it make more sense for this class to be destroyed earlier on, so that you
never end up during shutdown?

[sammiequon, 2017/03/28 23:12:08]

It would, but would this cause a bunch of other bugs? Also I'm not 100% certain
this will fix the crash. If I were to destroy this class early I would do it at
[1]? and then change all instances to check if the notification_manager() exists
before using it?

[1]
https://cs.chromium.org/chromium/src/chrome/browser/lifetime/application_life...

[stevenjb, 2017/03/29 00:21:33]

I would also be worried about dereferencing errors. We have a lot of calls (36)
to g_browser_process->notification_ui_manager() in the code. This seems like a
reasonable approach to me.

                                            Profile* profile) {
+  // We won't have time to process and act on this notification.
+  if (g_browser_process->IsShuttingDown())
+    return;
+
   if (Update(notification, profile))
     return;
 
   std::unique_ptr<ProfileNotification> profile_notification_ptr =
       base::MakeUnique<ProfileNotification>(profile, notification);
   ProfileNotification* profile_notification = profile_notification_ptr.get();
 
   ExtensionWelcomeNotificationFactory::GetForBrowserContext(profile)->
       ShowWelcomeNotificationIfNecessary(profile_notification->notification());
 
@@ skipping 242 matching lines @@
 }
 
 ProfileNotification* MessageCenterNotificationManager::FindProfileNotification(
     const std::string& id) const {
   auto iter = profile_notifications_.find(id);
   if (iter == profile_notifications_.end())
     return nullptr;
 
   return (*iter).second.get();
 }