Remove last usage functions from HostContentSettingsMap and clean up prefs

chrome/browser/notifications/platform_notification_service_impl.cc

Index: chrome/browser/notifications/platform_notification_service_impl.cc
diff --git a/chrome/browser/notifications/platform_notification_service_impl.cc b/chrome/browser/notifications/platform_notification_service_impl.cc
index 10c6a5466efe2ad66c68a8a7717c5f45d6d221e2..a3b208c932080984a698579a650e8064642d0467 100644
--- a/chrome/browser/notifications/platform_notification_service_impl.cc
+++ b/chrome/browser/notifications/platform_notification_service_impl.cc
@@ -319,9 +319,6 @@ void PlatformNotificationServiceImpl::DisplayNotification(
         base::Bind(&CancelNotification, notification.delegate_id(), profile_id,
                    profile->IsOffTheRecord());
   }
-
-  HostContentSettingsMapFactory::GetForProfile(profile)->UpdateLastUsage(
-      origin, origin, CONTENT_SETTINGS_TYPE_NOTIFICATIONS);
 }
 
 void PlatformNotificationServiceImpl::DisplayPersistentNotification(
@@ -356,9 +353,6 @@ void PlatformNotificationServiceImpl::DisplayPersistentNotification(
       NotificationCommon::PERSISTENT, notification_id, notification);
   content::RecordAction(
       base::UserMetricsAction("Notifications.Persistent.Shown"));
-
-  HostContentSettingsMapFactory::GetForProfile(profile)->UpdateLastUsage(
-      origin, origin, CONTENT_SETTINGS_TYPE_NOTIFICATIONS);
 }
 
 void PlatformNotificationServiceImpl::ClosePersistentNotification(