tmpfiles: Import eclass from upstream

This eclass is used by app-admin/sudo-1.8.25_p1-r1.

BUG=chromium:905444
TEST=Merged app-admin/sudo.

Change-Id: I915e04adfea3dd3aad6f6e91e7afd93b6422f42b
Reviewed-on: https://chromium-review.googlesource.com/1345310
Commit-Ready: Abe Levkoy <alevkoy@chromium.org>
Tested-by: Abe Levkoy <alevkoy@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed