[update_engine] use libchromeos.pc
[update_engine] use libchromeos.pc

BUG=chromium-os:24959
TEST=build

Change-Id: I11a9e2a117bc6ec454ebc6b8e75db0e27cccc326
Signed-off-by: Elly Jones <1693f95ea06ee6d7b2276cb599c3f4f33a951d9c@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/14021
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>

mjg59/update_engine,mjg59/update_engine,endocode/update_engine,endocode/update_engine,marineam/update_engine,marineam/update_engine,endocode/update_engine,mjg59/update_engine,marineam/update_engine,marineam/update_engine