Per discussion in webkit-dev, we need to implement DOM4 event constructors under a enable flag. For that purpose, we implement a [ConstructorConditional] IDL attribute.
Created attachment 183695 [details] Patch
Comment on attachment 183695 [details] Patch Clearing flags on attachment: 183695 Committed r140303: <http://trac.webkit.org/changeset/140303>
All reviewed patches have been landed. Closing bug.