Linux Printing: Add a CHECK to help track down a crash.
Linux Printing: Add a CHECK to help track down a crash.

BUG=70166
TEST=none
Review URL: http://codereview.chromium.org/6287005

git-svn-id: http://src.chromium.org/svn/trunk/src@71862 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 0fe6cc0420ac3835585ade5834766d29ab2d0ba3
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