Chrome Version:62.0.3166.0/9785.0.0 dev channel Peppy,Candy,Reks
OS:chrome

What steps will reproduce the problem?
(1)Sign in to user >> Launch chrome,Open Devtools and Dock to left
(2)In 'Customize and control DevTools' >>go to Settings ->Preferences ->Appearance and set Theme as 'Dark'
(3)Now navigate to Audits Tab and Observe weird scrollbar (Kindly refer video)

Actual:Weird scrollbar is seen 
Expected:Instead, it shouldn't be seen

This is a Regression issue as same is working fine in 61.0.3163.15/9765.8.0 dev channel Peppy

Note:
1.Issue is not seen for 'Light'theme
2.Issue is chrome specific, not seen in Linux,Windows OS for Dark theme

@Paulirish: Please confirm the above issue


 

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