The only usage in Source/WebKitLegacy/mac/WebView/WebView.mm doesn't need to use DeprecatedGlobalSettings. It can use Settings directly. Also, is this used anywhere? I can't find anything: https://searchfox.org/wubkat/search?q=audioSessionCategoryOverride&path=&case=false®exp=false
<rdar://problem/104244014>
Pull request: https://github.com/WebKit/WebKit/pull/17287
It's used by iOS.
I should not have closed this. It's just a bit more work.