When a notification is shown by the platform, the onshow event handler (which is the standard event) gets called, but not the ondisplay event handler (which is the legacy event).
The proper fix here, probably, would be to conflate the two, rather than treating the two separately.
Created attachment 161765 [details]
Committed r127321: <http://trac.webkit.org/changeset/127321>
(In reply to comment #3)
> Committed r127321: <http://trac.webkit.org/changeset/127321>
It broke 3 tests on Qt. Could you check it, please?
Here is the bug report: https://bugs.webkit.org/show_bug.cgi?id=95638