fast/regions/fixed-pos-region-in-nested-flow.html and fast/regions/fixed-inside-named-flow-zIndex.html are failing because the reference tests create backings for the fixed elements layers. Regions are not yet accelerated, don't create backings and this difference of behaviour causes a slight shift in the background color of the fixed elements.
Created attachment 210440 [details]
Comment on attachment 210440 [details]
Clearing flags on attachment: 210440
Committed r155030: <http://trac.webkit.org/changeset/155030>
All reviewed patches have been landed. Closing bug.