Deprecate native and extension notification delegates.

content/test/mock_platform_notification_service.cc

Index: content/test/mock_platform_notification_service.cc
diff --git a/content/test/mock_platform_notification_service.cc b/content/test/mock_platform_notification_service.cc
index 58db6968fe6370e92f3b5b40d25727755656d135..03fbd7caffb2e08a96036e81b2fa13b8f8b8853f 100644
--- a/content/test/mock_platform_notification_service.cc
+++ b/content/test/mock_platform_notification_service.cc
@@ -164,13 +164,9 @@ MockPlatformNotificationService::CheckPermissionOnIOThread(
 void MockPlatformNotificationService::Close(
     const std::string& notification_id) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  const auto non_persistent_iter =
-      non_persistent_notifications_.find(notification_id);
-  if (non_persistent_iter == non_persistent_notifications_.end()) {
-    NotificationEventDispatcher::GetInstance()->DispatchNonPersistentCloseEvent(
-        notification_id);
-    non_persistent_notifications_.erase(non_persistent_iter);
-  }
+  NotificationEventDispatcher::GetInstance()->DispatchNonPersistentCloseEvent(
+      notification_id);
+  non_persistent_notifications_.erase(notification_id);
 }
 
 void MockPlatformNotificationService::ReplaceNotificationIfNeeded(