In #4082 (comment) @MatsPalmgren wrote

I added three more columns that check each of the existing cases but with -webkit-appearance:none. [...]
Chrome also synthesizes the baseline differently depending on that property for type=checkbox for example (content-box vs margin-box).

It's also worth noting that the baseline is different for some of these controls. For example, type=color uses the content-box edges, whereas type=range use the margin-box edges in Firefox but the border-box edges in Chrome. We need to agree on these baselines and specify them somewhere.

Firefox and Safari also has different baseline for radio and checkbox depending on -webkit-appearance.