I have a few CLs in progress to do this but rather than removing libbase from run_oci completely we're just going to remove the large unnecessary parts of libbase (like dbus).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/20686fe66ec93bcd260ca320ae6f07b478918b9b

commit 20686fe66ec93bcd260ca320ae6f07b478918b9b
Author: Chirantan Ekbote <chirantan@chromium.org>
Date: Fri Apr 07 21:15:38 2017

update_engine: Add +dbus to IUSE variable

Add +dbus to the IUSE variable for update_engine.  This needs to be explicitly
set in the gyp invocation since the default behavior for the gyp file is to turn
off dbus.

BUG= 703929 
TEST='FEATURES=test emerge-$BOARD update_engine' still works

Change-Id: Ifef53bc1faebccba281dff5763899d3c16f2f891
Signed-off-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/457783
Reviewed-by: Stephen Barber <smbarber@chromium.org>

[modify] https://crrev.com/20686fe66ec93bcd260ca320ae6f07b478918b9b/chromeos-base/update_engine/update_engine-9999.ebuild