Classify API[1] is used by SafeBrowsing which is the only consumer of this interface. Baku is working on a refined interface with the ability to easily extend support for different features. We should consider using this API for SafeBrowsing. One benefit is that with new API, SafeBrowsing preference may be moved out from toolkit/component/url-classifier so we can decouple the "feature" and "safebrowsing protocol implementation" [1] https://searchfox.org/mozilla-central/rev/47edbd91c43db6229cf32d1fc4bae9b325b9e2d0/netwerk/url-classifier/nsChannelClassifier.cpp#229