Fix handling of --sanitize flag when building PNaCl toolchain.
Fix handling of --sanitize flag when building PNaCl toolchain.

BUG=None
R=dschuff@chromium.org

Review URL: https://codereview.chromium.org/1140523004

cohortfsllc/cohort-cocl2-sandbox,cohortfsllc/cohort-cocl2-sandbox,cohortfsllc/cohort-cocl2-sandbox,cohortfsllc/cohort-cocl2-sandbox,cohortfsllc/cohort-cocl2-sandbox,cohortfsllc/cohort-cocl2-sandbox