Linux: enable assertion in fontconfig code.
Linux: enable assertion in fontconfig code.

This doesn't trigger locally for me. I think it's safe to enable.
(Although the try servers are down for me, so I guess we'll find out.)

BUG=6291

Review URL: http://codereview.chromium.org/55036


git-svn-id: http://src.chromium.org/svn/trunk/src@12718 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: ad8840065fdf40cd28569ee1f5e5cd8d5313eee0
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser