For assignedNodes({flattened: true}), we need to include fallback contents when slots are empty.
<rdar://problem/28509151>
Created attachment 290051 [details] Fixes the bug
Created attachment 290052 [details] Fixes the bug
Comment on attachment 290052 [details] Fixes the bug Thanks for the review!
Comment on attachment 290052 [details] Fixes the bug Clearing flags on attachment: 290052 Committed r206534: <http://trac.webkit.org/changeset/206534>
All reviewed patches have been landed. Closing bug.