Make //content responsible for generating notification Ids

chrome/browser/notifications/persistent_notification_handler.h

Index: chrome/browser/notifications/persistent_notification_handler.h
diff --git a/chrome/browser/notifications/persistent_notification_handler.h b/chrome/browser/notifications/persistent_notification_handler.h
index e0d5e56e0d6b18956fdc8c17295dbeb62821a7a6..c251a0ebfeeb7e4e9af6c24360c47d8a914f871a 100644
--- a/chrome/browser/notifications/persistent_notification_handler.h
+++ b/chrome/browser/notifications/persistent_notification_handler.h
@@ -17,19 +17,16 @@ class PersistentNotificationHandler : public NotificationHandler {
   PersistentNotificationHandler();
   ~PersistentNotificationHandler() override;
 
-  // NotificationHandler implementation
+  // NotificationHandler implementation.
   void OnClose(Profile* profile,
                const std::string& origin,
                const std::string& notification_id,
                bool by_user) override;
-
   void OnClick(Profile* profile,
                const std::string& origin,
                const std::string& notification_id,
                int action_index) override;
-
   void OpenSettings(Profile* profile) override;
-
   void RegisterNotification(const std::string& notification_id,
                             NotificationDelegate* delegate) override;