Disable the layout dimensions optimization for regions, since auto height regions can change size without being marked for layout.
Created attachment 249350 [details] Patch
Comment on attachment 249350 [details] Patch Clearing flags on attachment: 249350 Committed r181909: <http://trac.webkit.org/changeset/181909>
All reviewed patches have been landed. Closing bug.
Re-opened since this is blocked by bug 143034