Chrome Version: 66.0.3359.106 (Official Build) 580e8ed9017368bf40061fa0b9618ad381082b0a-refs/branch-heads/3359@{#693}(64 bit)
OS: Mac 10.13.5(Mac Touchbar), Mac 10.12.6 Retina

What steps will reproduce the problem?
(1) Launch Chrome, navigate to chrome://settings/resetProfileSettings?origin=userclick.
(2) Resize the browser window to minimum(Please refer attached video).
(3) Try to scroll within the 'Reset Settings' overlay using touchpad or arrow keys and observe.

Actual Result: The outer scrollbar in the 'Reset Settings' overlay does not appear.
Expected Result: The outer scrollbar in the 'Reset Settings' overlay should be seen.

This is regression issue broken in ‘M-63’ and providing the bisect using per-revision bisect,
Good build: 63.0.3207.0(Revision: 499830)
Bad build: 63.0.3208.0(Revision: 500160)

You are probably looking for a change made after 500130 (known good), but no later than 500131 (first known bad).

CHANGELOG URL:

The script might not always return single CL as suspect as some perf builds might get missing due to failure.

https://chromium.googlesource.com/chromium/src/+log/fd751b0f7d36086c8c2d974a98e8466e89344b5a..5282c59aa39d5ced02eea99766ab471da7351d1e

Suspect: https://chromium.googlesource.com/chromium/src/+/5282c59aa39d5ced02eea99766ab471da7351d1e

@scottchen: 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 Windows(7,8,8.1,10), Mac(10.13.1) and Linux(14.04).
2. Issue is also seen on Stable(build #65.0.3325.181), Dev(build #67.0.3393.4) and Canary(build #67.0.3395.0)

Thank You!


 

Deleted: ActualVideo.mov 9.3 MB

	ActualVideo.mov 9.3 MB View Download

Deleted: ExpectedVideo.mov 8.5 MB

	ExpectedVideo.mov 8.5 MB View Download