src/vs/workbench/services/userDataSync/browser/userDataSyncWorkbenchService.ts/UserDataSyncWorkbenchService/onBeforeShutdown
class UserDataSyncWorkbenchService:	private async onBeforeShutdown(manualSyncTask: IManualSyncTask): Promise<boolean> {
		const result = await this.dialogService.confirm({
			type: 'warning',
			message: localize('sync in progress', "Settings Sync is being turned on. Would you like to cancel it?"),
			title: localize('settings sync', "Settings Sync"),
			primaryButton: localize({ key: 'yes', comment: ['&& denotes a mnemonic'] }, "&&Yes"),
			secondaryButton: localize({ key: 'no', comment: ['&& denotes a mnemonic'] }, "&&No"),
		});
		if (result.confirmed) {
			await manualSyncTask.stop();
		}
		return !result.confirmed;
	}