On S3, for example, it's possible to delete multiple objects within one request (http://docs.aws.amazon.com/AmazonS3/latest/API/multiobjectdeleteapi.html).

The AbstractFilesystemResolver may also delegate it further to the `Symfony\Component\Filesystem\Filesystem` (which current implementation iterates for itself).

I think the old DoctrinePHPCR would also be capable of doing so.