SpeedLine vs the first paint API

[soulgalore]

Hi @paulirish do you know how accurate the trace log is? I've been trying out using SpeedLine to get visual metrics from our Android devices to get rid of the overhead using a video. It works great but (there's always a but) the first visual change differs a lot for first paint reported from the paint timing API. In this example the first change reported from Speed Line is 778ms and the paint timing API report 1.27s.

Manually looking at the trace log in devtools, it looks like Speed Line is correct (I added the orange frame to just see when we start the navigation):

Is this something you have seen in your tests?