Chrome Version:71.0.3578.20 (Official Build) be2b6ea800808b865cd07ab76acf9e2a009c045a-refs/branch-heads/3578@{#254} 32/64 bit
OS:Mac(10.13.1, 10.13.6, 10.14.1), Linux(14.04), Windows(7,8,10)

What steps will reproduce the problem?
1. Launch chrome, navigate to chrome://settings/onStartup page and select "Open a specific page or set of pages" option.
2. Add enough entries by clicking on "Add a new page" such that vertical scrollbar appears.
3. Bring focus to 'Add a new Page' , scroll the entries and observe.

Actual Result  : Upper border of blue focus ring on 'Add a new Page' appears distorted while scrolling.
Expected Result: Upper border of blue focus ring on 'Add a new Page' should not appear distorted while scrolling.

This is a regression issue broken in ‘M-63’ and below is the bisect info :
Good Build :63.0.3211.0 (Revision : 500754)
Bad Build  :63.0.3212.0 (Revision : 500792)

You are probably looking for a change made after 500771 (known good), but no later than 500772 (first known bad).
CHANGE-LOG 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/8316ce5af3eaa219e5b9705db4ccef535d8ad1e0..c9a3169d206e066bf33f3b4e399cce5ac0782c61	

Suspect : https://chromium.googlesource.com/chromium/src/+/c9a3169d206e066bf33f3b4e399cce5ac0782c61

@dschuyler: 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: Issue is also seen on Canary build #72.0.3589.0 and Beta/Stable build #70.0.3538.67

Thank You!
 

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