Chrome Version: 71.0.3578.20 Revision be2b6ea800808b865cd07ab76acf9e2a009c045a-refs/branch-heads/3578@{#254}(32/64 bit)
OS: Windows 7

What steps will reproduce the problem?
(1) Launch chrome, open chrome://apps page, and right click on any app then select 'Open as Window' option.
(2) Click on same app (it will open in separate window) resize it and observe while resizing.

Actual: Unwanted blink of black patch is seen while resizing app window.

Expected: No such a blink should seen.

This is a win-7 specific regression issue, broken in 'M70', below is bisect info:

Good Build:70.0.3507.0(Revision: 578962)
Bad Build: 70.0.3508.0(Revision: 579241)

You are probably looking for a change made after 578963 (known good), but no later than 578966 (first known bad).

CHANGELOG URL:

https://chromium.googlesource.com/chromium/src/+log/a71756341b5f561768144f0ba51b1567783884d5..3a49dbc584bb1e0a8242e2436270117daea70605

Suspect: https://chromium.googlesource.com/chromium/src/+/dd0ee5d6c3c38be7faa7a2b4eeede83270770e19

alancutter@: Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Note: 
1.Issue is not seen on Windows(8,10.8.1),Mac(10.13.1,10.13.6,10.14.1) and Linux(14.04 LTS)
2.Unable to capture actual video for the above issue as issue is not seen in video.
 

Deleted: Expected_Window.mp4 2.3 MB

	Expected_Window.mp4 2.3 MB View Download