Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a bug report that matches the one I want to file, without success.

Electron Version

42.2.0

What operating system(s) are you using?

Windows, Other Linux

Operating System Version

Windows 11 25H2, CachyOS (Wayland)

What arch are you using?

x64

Last Known Working Electron version

41.0.0

Does the issue also appear in Chromium / Google Chrome?

No

Expected Behavior

Centering a window with frame: false should center it (Windows/X11) or do nothing (Wayland).

Actual Behavior

The window shrinks.

Testcase Gist URL

https://gist.github.com/mitchchn/5455055d090ede993ebfbe0094dfd2ba

Additional Information

This is because the NativeWindowViews::Center() API does not account for insets which now exist on frameless windows on both Linux and Windows.