I was wheel-scrolling third_party/WebKit/LayoutTests/animations/animationworklet/scroll-timeline.html repeatedly and found that ~1/10 times I can trigger the negative offset DCHECK when scrolling back to the top:

[1:8:1112/110307.452749:FATAL:scroll_timeline.cc(63)] Check failed: offset.y() >= 0 (-5.72205e-06 vs. 0)

(I have a local patch in, hence the different code line from ToT, but I think it should reproduce without my patch).

Majid mentioned:

"Maybe our scroll animation curves can cause this 😮
wheel scroll is animated"