I messed up with the pixel formats. Patch incoming, sorry for the inconvenience :)
Created attachment 148687 [details] Patch
Alexis, would you qualify to review this patch? :)
Comment on attachment 148687 [details] Patch Clearing flags on attachment: 148687 Committed r120964: <http://trac.webkit.org/changeset/120964>
All reviewed patches have been landed. Closing bug.