src/vs/workbench/services/workingCopy/common/storedFileWorkingCopyManager.ts/StoredFileWorkingCopyManager/onBeforeShutdownWeb
class StoredFileWorkingCopyManager:	private onBeforeShutdownWeb(): boolean {
		if (this.workingCopies.some(workingCopy => workingCopy.hasState(StoredFileWorkingCopyState.PENDING_SAVE))) {
			// stored file working copies are pending to be saved:
			// veto because web does not support long running shutdown
			return true;
		}

		return false;
	}