Do some hardening in XPCServiceEventHandler() to deal with unexpected values and add some more logging as well.
<rdar://66837596>
Created attachment 431035 [details] Patch
Created attachment 431037 [details] Patch
Comment on attachment 431037 [details] Patch r=me
Committed r278716 (238684@main): <https://commits.webkit.org/238684@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 431037 [details].