tables/mozilla/bugs/bug20804.html: mark flakey on Linux
tables/mozilla/bugs/bug20804.html: mark flakey on Linux

BUG=38534

git-svn-id: http://src.chromium.org/svn/trunk/src@42006 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 5910d017017f1a7eae3d9a94fe0c3b7140096001
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