AU: when compiling locally, use cros-debug for libchrome
AU: when compiling locally, use cros-debug for libchrome

BUG=6797
TEST=compiled locally. saw this fix the error

Review URL: http://codereview.chromium.org/3386007

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