This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
sync property of the
ServiceWorkerRegistration interface returns a reference to the
SyncManager interface, which manages background synchronization processes.
mySyncManager = ServiceWorker.sync
||Firefox Mobile (Gecko)
||Chrome for Android
 Service workers (and Push) have been disabled in the Firefox 45 and 52 Extended Support Releases (ESR.)
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