Chrome Version:62.0.3176.0/9823.0.0 dev-channel Daisy,Candy,Minnie
OS:Chrome

What steps will reproduce the problem?
(1)In OOBE screen,go to Ubertray ->Click on date & time to open 'check your system time'overlay
(2)In 'check your system time'overlay -> Click on System date drop down arrow to open calendar
(3)Now press and hold UP arrow key in keyboard and Observe (Kindly refer video)

Actual:Flickering of Calendar window is seen
Expected:No such flickering should be seen

This is a Non-Regression issue seen from M-55

Note: Issue is not applicable to Linux,Windows OS

@alemate: Please confirm the issue