service worker: Add a netlog event for navigation preload

net/log/net_log_event_type_list.h

Index: net/log/net_log_event_type_list.h
diff --git a/net/log/net_log_event_type_list.h b/net/log/net_log_event_type_list.h
index 53c84f4e4986fc63a9eb455be39d49b40d3a9d68..b3325d74de5e9bae8469e3e009054b6531ff6354 100644
--- a/net/log/net_log_event_type_list.h
+++ b/net/log/net_log_event_type_list.h
@@ -2232,6 +2232,9 @@ EVENT_TYPE(SERVICE_WORKER_FETCH_EVENT)
 // }
 EVENT_TYPE(SERVICE_WORKER_SCRIPT_LOAD_UNHANDLED_REQUEST_ERROR)
 
+// This event is emitted when a navigation preload request is created.
+EVENT_TYPE(SERVICE_WORKER_NAVIGATION_PRELOAD_REQUEST)
+
 // ------------------------------------------------------------------------
 // Global events
 // ------------------------------------------------------------------------