It should be possible to dispatch events on template documents. Firefox supports this. Chrome does not but this is likely not intentional as Chrome generally supports dispatching events on frameless documents.
Created attachment 290100 [details] Patch
Comment on attachment 290100 [details] Patch Clearing flags on attachment: 290100 Committed r206541: <http://trac.webkit.org/changeset/206541>
All reviewed patches have been landed. Closing bug.