Definition
Service Workers Nightly defines ServiceWorkerContainer
[SecureContext, Exposed=(Window,Worker)]
interface ServiceWorkerContainer : EventTarget {
readonly attribute ServiceWorker? controller;
readonly attribute Promise<ServiceWorkerRegistration> ready;
[NewObject] Promise<ServiceWorkerRegistration> register(USVString scriptURL, optional RegistrationOptions options = {});
[NewObject] Promise<(ServiceWorkerRegistration or undefined)> getRegistration(optional USVString clientURL = "");
[NewObject] Promise<FrozenArray<ServiceWorkerRegistration>> getRegistrations();
undefined startMessages();
// events
attribute EventHandler oncontrollerchange;
attribute EventHandler onmessage; // event.source of message events is ServiceWorker object
attribute EventHandler onmessageerror;
};