Zen, a customer wants to load a wallpaper from a file share. Any reason why this shouldn't work?

What about the device wallpaper? I assume right now shares are mounted inside the user session, right? This would be too late for device wallpapers. Will there be a policy to mount a share on the login screen?

tldr; not easily right now.

This wouldn't work right now for a few reasons. Chromad could use smbclient to manually do this though that seems a little clunky.

The problems with doing this are

a) File System Providers currently are bound to user sessions.
b) File system providers need to be mounted to fit with the current model of the file manager. eg. even though technically an smb url is just one large single namespace the files app expects to be able to call 'something' the root.
c) Per b) there's no notion in CrOS of a free form single smb resource like smb://foo/bar/image.jpg

We have talked previously about an implicit temporary mount, which is also needed to support the use case like someone sends an email with a link smb://foo/bar/my_doc.pdf - in windows this just works, but we would need to have some specialized handling to do this in Chrome OS. One idea is to allow a provider to register as a scheme handler (eg smb://). We do something like this for file type/extension, but not on a entire url schemes.

We do have a policy in the js extension (which we will eventually add to the new native one) that lets admins pre mount shares for users (I suppose we could have the same for a device for these cases). Again the problem here is that there's no way on Chrome OS to address a mount point explicitly (we don't really have places that can deal with absolute paths) so you wouldn't be able to point to it (and it would likely not be the same as the original url so it might need to be set differently for CrOS and windows if a group policy is shared).

There is work planned later this year to expose SMB (and other file system providers) via FUSE, which should in theory make things have a specific location within the local file system.