When ACCELERATED_COMPOSITING, composited layers will render on top of scrollbars.
Created attachment 57265 [details] Proposed patch
Comment on attachment 57265 [details] Proposed patch ok.
Comment on attachment 57265 [details] Proposed patch Clearing flags on attachment: 57265 Committed r60385: <http://trac.webkit.org/changeset/60385>
All reviewed patches have been landed. Closing bug.