Version: 56.0.2914.3 (Official Build) dev (64-bit)
OS: Linux

What steps will reproduce the problem?
(1) load the attached testcase
(2)
(3)

What is the expected result?
The two grids should look the same.

What happens instead?
The row height in the first grid is too large.
(illustrated by the height of the cyan colored item)

Relevant CSS Grid spec text:
https://drafts.csswg.org/css-grid/#min-size-auto
"
... also applies an automatic minimum size in the specified axis
to grid items whose 'overflow' is 'visible'.
"

The grey grid item has "overflow:hidden" so the "automatic minimum size"
part of "Implied Minimum Size of Grid Items" does NOT apply.

(I suspect that's what you're doing because if I remove
the "overflow:hidden" then I get the same result in Firefox.)
 

Deleted: grid-item-auto-min-size-overflow-hidden.html 845 bytes

grid-item-auto-min-size-overflow-hidden.html 845 bytes View Download