Chrome Version: 71.0.3578.27 (Official Build) Revision	d7850e07856a010c464bc7ea52e4ee10ca5965ce-refs/branch-heads/3578@{#361}(32/64-bit)
OS: Windows(7,8,8.1,10)

Pre-condition: Enable "Enable using the Google local NTP" ,"New Tab Page Background Selection" and "New Tab Page Custom Links" flags under chrome://flags.

What steps will reproduce the problem?
1. Launch chrome, open NTP, resize browser window from RHS to the maximum possible limit.
2. Click on the gear icon > click on 'Chrome backgrounds'(observe that tiles appear one in a row).
3. On 'Select a collection' overlay ,select any category to open another overlay listing the wallpapers.
4. Click on any wallpaper to select it then press space bar to scroll downwards through the list.
5. Once we reach the end of the overlay(last tile) observe that the NTP also gets scrolled.
6. Now try scrolling upwards by pressing up arrow key and observe.

Actual Result  : Only the wallpaper list gets scrolled back to original position whereas the ntp does not get scrolled back to original position.
Expected Result: The wallpaper list as well as NTP should scroll back to original position.

This is a regression issue broken in ‘M-70’ and below is the 'per-revision' bisect information:
Good Build : 70.0.3532.0 (Revision : 585633)
Bad Build  : 70.0.3533.0 (Revision : 586155)

You are probably looking for a change made after 585916 (known good), but no later than 585917 (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/bedc36ac9b37703dde0646017740ecd31c485e76..cdfd0835f3bb7598748a5eff0b1ec368b64f0eb1

Suspect: https://chromium.googlesource.com/chromium/src/+/cdfd0835f3bb7598748a5eff0b1ec368b64f0eb1

@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.

Kindly refer the attached screen-cast.

Note:Issue is reproducible on current Dev build #72.0.3590.0 and latest Canary build #72.0.3595.0

Thank you

 

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	ExpectedVideo.mp4 1.3 MB View Download

Deleted: ActualVideo.mp4 1.1 MB

	ActualVideo.mp4 1.1 MB View Download