In general, browser benchmarks seem to often favor Firefox in terms of startup and first interaction timings, and often favor Chrome when it comes to crunching large amounts of data through JavaScript.
I.e. for pages which use small amounts of JavaScript, but call into it quickly after loading, Firefox tends to come out on top. But for pages which load lots of JavaScript and then run it constantly, Chrome tends to come out on top.

We're usually talking milliseconds-level of difference here though. So if you're using a mobile browser or a low-power laptop, then the difference is often not measurable at all, unless the page is specifically optimized for one or the other.