The :unresolved pseudo-class [CSS3-SELECTORS] must match all custom elements whose custom element constructor has not yet been invoked.
Created attachment 273171 [details]
The spec has been updated to now define :defined instead:
Created attachment 273549 [details]
Adds the support
Created attachment 273550 [details]
Fixed change logs
Committed r197952: <http://trac.webkit.org/changeset/197952>