Chrome Version: Version 62.0.3202.29 (Official Build) beta (64-bit)
OS: Linux but probably others

What steps will reproduce the problem?
(1) Zoom to 125%
(2) Use any textbox and misspell something on the same line as the cursor.
(3) Fix the spelling mistake so the marker should disappear.

Might depend on having a 4K display, although I do not have HighDPI settings active.

What is the expected result? All traces of the marker are gone

What happens instead? One row of pixels from the top of the marker remain on screen. Even more odd, as the cursor blinks those pixels appear and disappear out of phase with the cursor (i.e. cursor visible, marker off, and vice versa).

I'll get a test case up when I have time. Assigning to myself until I get that test.