Close window with last tab: Never creates extra newtabs when closing DevTools windows

[MiningTcup]

OS/Platform

Arch Linux

Installed

OS/Platform's package manager

Version

Version 149.0.7827.114 (Official Build, ungoogled-chromium) Arch Linux (64-bit)

Have you tested that this is not an upstream issue or an issue with your configuration?

• I have tried reproducing this issue in Chrome and it could not be reproduced there
• I have tried reproducing this issue in vanilla Chromium and it could not be reproduced there
• I have tried reproducing this issue in ungoogled-chromium with a new and empty profile using --user-data-dir command line argument and it could not be reproduced there

Description

When closing a tab with a connected popup-DevTools window, with Close window with last tab: Never, an extra newtab is opened.

How to Reproduce?

1. Go to chrome://flags/ and set "Close window with last tab" to "Never."
2. Open a new tab and press Ctrl+Shift+I to open DevTools
3. Click the three dots in the upper-right and change "Dock Side" to the popup-window option (the leftmost option).
4. Go back to the tab which DevTools is monitoring and close it with Ctrl+W.

Actual behaviour

One more newtab than should be opened is opened (two newtabs if the closed tab was actually the last tab, or one if it was not).

Expected behaviour

Only one newtab should be opened if the tab was actually the last tab, or none if it was not.

Relevant log output

none

Additional context

I guess it's counting the DevTools as the last tab in a window, so it opens a new tab (in the original window) to try to keep the DevTools window open. Note that it happens whether you Ctrl+W the main-window tab or the DevTools window. It does not happen if you close the DevTools window using a different method. This also happens on my main browser, Helium, but I tested it in ungoogled-chromium.

ungoogled-flag-bug.mp4