Unreviewed GTK gardening.

* platform/gtk/TestExpectations: Adding a failure expectation for the failing
fast/regions/seamless-iframe-flowed-into-regions.html added in r143256.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143307 268f45cc-cd09-0410-ab3c-d52691b4dbfc