src/vs/platform/userDataSync/common/userDataSyncEnablementService.ts/UserDataSyncEnablementService/onDidStorageChange
class UserDataSyncEnablementService:	private onDidStorageChange(storageChangeEvent: IStorageValueChangeEvent): void {
		if (storageChangeEvent.scope !== StorageScope.APPLICATION) {
			return;
		}

		if (enablementKey === storageChangeEvent.key) {
			this._onDidChangeEnablement.fire(this.isEnabled());
			return;
		}

		const resourceKey = ALL_SYNC_RESOURCES.filter(resourceKey => getEnablementKey(resourceKey) === storageChangeEvent.key)[0];
		if (resourceKey) {
			this._onDidChangeResourceEnablement.fire([resourceKey, this.isResourceEnabled(resourceKey)]);
			return;
		}
	}