src/vs/platform/userDataSync/common/userDataSyncService.ts/UserDataSyncService/hasLocalData
class UserDataSyncService:	async hasLocalData(): Promise<boolean> {
		// skip global state synchronizer
		const synchronizers = [this.settingsSynchroniser, this.keybindingsSynchroniser, this.snippetsSynchroniser, this.extensionsSynchroniser];
		for (const synchroniser of synchronizers) {
			if (await synchroniser.hasLocalData()) {
				return true;
			}
		}
		return false;
	}