Minimize the delegate dependencies for non persistent notifications.

chrome/browser/notifications/persistent_notification_handler.cc

Index: chrome/browser/notifications/persistent_notification_handler.cc
diff --git a/chrome/browser/notifications/persistent_notification_handler.cc b/chrome/browser/notifications/persistent_notification_handler.cc
index 16b62654d2d925ffe2a566326c7d074ec0a9cbea..fa55ebc17bffb9dbbad8fbf559be26904b52d229 100644
--- a/chrome/browser/notifications/persistent_notification_handler.cc
+++ b/chrome/browser/notifications/persistent_notification_handler.cc
@@ -41,9 +41,3 @@ void PersistentNotificationHandler::OnClick(
 void PersistentNotificationHandler::OpenSettings(Profile* profile) {
   NotificationCommon::OpenNotificationSettings(profile);
 }
-
-void PersistentNotificationHandler::RegisterNotification(
-    const std::string& notification_id,
-    NotificationDelegate* delegate) {
-  // Nothing to do here since there is no state kept.
-}