EventSender is mainly the old event handling code. An example of porting to the new event handling code is https://bugs.webkit.org/show_bug.cgi?id=227915 Here's a list of all usages: https://webkit-search.igalia.com/webkit/search?q=EventSender.h&path=&case=false®exp=false
<rdar://problem/81869986>
*** This bug has been marked as a duplicate of bug 202843 ***