If you have cookies that need to be read in a 3p context (federated auth for instance), you must UA sniff in order to figure out if setting samesite=none is goi

If you have cookies that need to be read in a 3p context (federated auth for instance), you must UA sniff in order to figure out if setting samesite=none is going to break your cookies, do nothing, or be required for your cookies - just across three versions of Chrome. Then there are the apps that forked Chromium 66 and then renamed it, so you can't tell what version it is. We're planning to just break them, since it's impossible to tell what to do there.