Update ServiceWorkerContainer interface description - EventHandlers
Update ServiceWorkerContainer interface description - EventHandlers

justinleoye/ServiceWorker,martinthomson/ServiceWorker,mkruisselbrink/ServiceWorker,chadoliver/ServiceWorker,justinleoye/ServiceWorker,karolklp/ServiceWorker,martinthomson/ServiceWorker,chadoliver/ServiceWorker,slightlyoff/ServiceWorker,zuzusik/ServiceWorker,mkruisselbrink/ServiceWorker,zuzusik/ServiceWorker,karolklp/ServiceWorker,chadoliver/ServiceWorker,martinthomson/ServiceWorker,justinleoye/ServiceWorker,karolklp/ServiceWorker,slightlyoff/ServiceWorker,zuzusik/ServiceWorker