interface SyncStatusObserver (source)
An interface for consumers that wish to observer “sync lifecycle” events.
Gets called if sync encounters an error that’s worthy of processing by status observers.
Gets called at the end of a sync, after every configured syncable has been synchronized. A set of enabled SyncEngines could have changed, so observers are expected to query SyncEnginesStorage.getStatus.
Gets called at the start of a sync, before any configured syncable is synchronized.