Persistent ServiceWorker https://guest271314.github.io/persistent-serviceworker/ (EventSource, FetchEvent) References: https://bugs.chromium.org/p/chromium/issues/detail?id=1152255 https://bugs.chromium.org/p/chromium/issues/detail?id=1189678 w3c/ServiceWorker#980 w3c/ServiceWorker#1558 w3c/ServiceWorker#1624