This test fails on Qt and GTK since it has been introduced in http://trac.webkit.org/changeset/136857
with 1 pixel difference in the vertical coordinate of the green box. You can see the image differences here:
I will skip this test on Qt until the proper fix.
The original bug can be found at
Created attachment 179074 [details]
Comment on attachment 179074 [details]
Clearing flags on attachment: 179074
Committed r137518: <http://trac.webkit.org/changeset/137518>
All reviewed patches have been landed. Closing bug.