(Note, this is bad enough that I'd consider it a blocker to shipping single-tab mode.)

 Issue 857379  has been merged into this issue.

If this is truly the same as  bug 857379 , I think it needs to go back to P1, since that bug's symptoms affected more than just single-tab mode.

Reading  bug 857379 , it seems to be directly related to single-tab mode?

Please feel free to dedup if these turn out to be separate issues

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/901634eeb056e61914c0b70b43adff655d156c2b

commit 901634eeb056e61914c0b70b43adff655d156c2b
Author: Tom Anderson <thomasanderson@chromium.org>
Date: Thu Jul 12 18:42:32 2018

Fix tabstrip edges not redrawing when entering/leaving single tab mode

BUG= 860859 
R=pkasting

Change-Id: I9766d6c175fa6bdd8906c58448bf94ae85a17141
Reviewed-on: https://chromium-review.googlesource.com/1135512
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574645}
[modify] https://crrev.com/901634eeb056e61914c0b70b43adff655d156c2b/chrome/browser/ui/views/frame/opaque_browser_frame_view.cc

Hi,

Verifying the the above bug referring to 857379, using the below given steps.

1. Launch chrome and navigate to chrome://settings/appearance and set 'Classic' theme.
2. Close the browser and launch the browser again. (with 1 NTP)
3. Open one more NTP, close one of the NTP and observe Tab-Strip.

Verified the issue on Linux(14.04 LTS) and Windows(7,8,8.1,10) OS and issue is fixed.

Kindly refer the screen-cast from the below given link.
https://drive.google.com/drive/folders/1Dm9RmaumwZARehR4O6sdtAxXHHdZwHDl?usp=sharing

Thank You!

re c#13 thanks for the verification.