Why does it say “CSSLayerBlockRule” in Chrome Console?

I am working on a typical “snake” game in js, and came across the following output on Chrome’s console:

console output

The prints from my script are working fine, but I cannot find any documentation on the last two lines. They do not seem like errors to me, but what are they?

EDIT: Since i got some downvotes, could someone point out my mistake in asking this question?