ready-to-show never fires for hidden windows with titleBarOverlay on Windows (regression in 44.4.x)

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

44.4.1

What operating system(s) are you using?

Windows

Operating System Version

Windows 11 (10.0.26200)

What arch are you using?

x64

Last Known Working Electron version

44.1.1

Does the issue also appear in Chromium / Google Chrome?

I don't know how to test

Expected Behavior

A BrowserWindow created with show: false emits ready-to-show after its first paint, so the window can be shown without a flash — this works on 44.1.1.

Actual Behavior

On 44.4.1 the event never fires, so an app that waits for ready-to-show to call show() stays invisible forever. The page itself loads normally (did-finish-load fires, the renderer is alive, CDP works). To end users the app appears not to start. This broke our released Windows build for every user.

Output of the testcase on both versions:

electron 44.1.1 / Chromium 152.0.7977.65: RESULT ready-to-show=true did-finish-load=true
electron 44.4.1 / Chromium 152.0.7977.78: RESULT ready-to-show=false did-finish-load=true

Testcase Gist URL

https://gist.github.com/huang-sh/eec4ca48656c393bd275dc605af55673

Additional Information

Bisecting the window options on 44.4.1:

• Removing titleBarOverlay makes ready-to-show fire again — the overlay on an initially-hidden window is what suppresses it.
• backgroundThrottling: false and webviewTag: true are not involved (both fire fine without the overlay).
• Only verified on Windows; not tested on macOS/Linux.

Workaround we shipped: fall back to showing the window from did-finish-load after a short delay. Happy to test a fix build on short notice.