Add expected failure for "dns-prefetch-control.html" which has been flaky on linux for a while.
Add expected failure for "dns-prefetch-control.html" which has been flaky on linux for a while.

The cause of the flake is an extra output line (warning from pkix_CacheCertChain_Add), see bug for details.

TBR=tony
BUG=14009
Review URL: http://codereview.chromium.org/126077

git-svn-id: http://src.chromium.org/svn/trunk/src@18329 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: da928159c4d3428bd2996e26d287c394edab60c6
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