At a glance, it is OK just converting deprecatedShadowAncestorNode() to shadowHost() in Editor.cpp, since all the occurrence are in a shadow tree, and no need to worry about nested shadow dom here.
Created attachment 185389 [details]
Comment on attachment 185389 [details]
Clearing flags on attachment: 185389
Committed r141225: <http://trac.webkit.org/changeset/141225>
All reviewed patches have been landed. Closing bug.