This is a regression caused by https://bugs.webkit.org/show_bug.cgi?id=108181
Created attachment 185473 [details] Screenshot with a missing splitter
Created attachment 185476 [details] Patch
Comment on attachment 185476 [details] Patch Clearing flags on attachment: 185476 Committed r141270: <http://trac.webkit.org/changeset/141270>
All reviewed patches have been landed. Closing bug.