Chrome version : 68.0.3432.3 (Official Build) Revision 5aacd4d4350de37f394edd3095576d2bc7daf56c-refs/branch-heads/3432@{#6}(64 bit) 

OS : Mac(10.12.6 , 10.13.1 , 10.13.5) OS 

Steps to reproduce:
1.Launch chrome and press 'ctrl+t' to open multiple tabs(i.e open atleast 35 tabs).
2.Now right click on first tab and click on 'close tabs to the right' option.
3.Observe.

Actual Result:  Animation is not seen smooth on closing multiple tab.
Expected Result:  Animation should be seen smooth on closing multiple tab.

This is a regression issue broken in ‘M-62’ and will soon update other bisect info.
Good build: 62.0.3173.0 (Revision : 490803)
Bad build: 62.0.3174.0  (Revision : 491203)

You are probably looking for a change made after 491059 (known good), but no later than 491060 (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/be2ad6c6b68386e5a8c6c3615dff5d26a4a6bf32..f5345de13668f0176b11126a7ae391dad5b4ad0f

Suspect: https://chromium.googlesource.com/chromium/src/+/f5345de13668f0176b11126a7ae391dad5b4ad0f

@erikchen: Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.

Note: Issue is not seen on Windows(7,8,8.1,10) and and Linux(14.04 LTS) OS.

Thank you.
 

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