libchromeos: move mountpoints into subdirectories

This lets us set permissions that apply to all user directories or all root
directories.

BUG=chromium-os:16681,chromium-os:20778
TEST=None

Change-Id: I240fe94590b592a983d0a9f37addf2b0cd081c1e
Signed-off-by: Elly Jones <ellyjones@chromium.org>
Reviewed-on: http://gerrit.chromium.org/gerrit/10173
Reviewed-by: Will Drewry <wad@chromium.org>
1 file changed