Chrome Version: 72.0.3590.0 (Official Build) (64-bit) Revision ec242826af28a2b3c3b47390ab6141cfe26fe9e7-refs/branch-heads/3590@{#1} (64-bit)

OS: Mac (10.13.6, 10.14.1)

Pre-condition: Enable the flag 'Enable using the Google local NTP' and 'New Tab Page Background Selection' from chrome://flags/

What steps will reproduce the problem?
(1) Launch chrome, open NTP and click on gear icon then select 'Choose background' option ('Select a collection' overlay will open).
(2) Select any collection and scroll the wallpaper page.
(3) Now observe the scrollbar.

Actual Result: Scrollbar is not seen properly over 'Choose Background' wallpaper overlay.

Expected Result: Scrollbar should be seen properly over 'Choose Background' wallpaper overlay.

This is a Regression issue seen from 'M-71' and below is the manual regression range:
Good Build: 71.0.3558.0 (Revision: 593043)
Bad Build:  71.0.3559.0 (Revision: 593399)

(Unable to provide bisect using Per-revision script as Traceback error message is thrown. Also, tried bisecting on other machines and same error is thrown. Hence, providing suspect using Chromium bisect)

Chromium Bisect info:

You are probably looking for a change made after 593067 (known good), but no later than 593076 (first known bad).

CHANGE-LOG URL:

https://chromium.googlesource.com/chromium/src/+log/fe6e02d2be1c8bfe626db5a411d23d61165a6aca..3e4e10cf8afeff34ed2275d022a5fffae14904a2

Suspecting: r593074 ?

@sweilun: 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 also seen on M-71 Dev (build #71.0.3578.20).
2. Issue is not seen on Windows (7, 8, 8.1, 10) & Linux (14.04 LTS).

Kindly refer the attached screen-cast.

Thank You..!!

 

Deleted: Actual Video.mov 8.6 MB

	Actual Video.mov 8.6 MB View Download

Deleted: Expected Video.mov 5.8 MB

	Expected Video.mov 5.8 MB View Download