Sadly we have no automated way to detect dead code, and instead must wait for humans to stumble upon it. I only noticed these because WebProcessPool::sendToAllProcessesRelaunchingThemIfNecessary had a suspicious FIXME (which dates back to r129701).
Created attachment 395834 [details] Patch
Committed r259743: <https://trac.webkit.org/changeset/259743> All reviewed patches have been landed. Closing bug and clearing flags on attachment 395834 [details].
<rdar://problem/61468898>