The following layout test is failing on GTK+
The second frame of the gif is being rendered in a slightly brighter green…
Committed r196027: <http://trac.webkit.org/changeset/196027>
Careful with the webkit-patch script, it will close the bug automatically if you link to it in the changelog! I just leave the bug reference out of the changelog but there's probably a way to make it not do that.
Fixed in r215179.