[Chromium] Reloading the welcome page after Firefox has been detected causes layout issues for a short time

[acornestean]

Description:
After performing the necessary steps for the Chromium extension to detect Firefox as per the instructions from the “Native Messaging Changes” section for the Alpha Build V2 extension from https://github.com/mozilla-extensions/firefox-bridge/releases and reloading the welcome page, the page’s layout becomes broken for a short period of time. See attached screenshot.

The layout issue persists longer on Windows and less on macOS. Chrome, Brave, Edge and Opera are all affected.

Note that the layout issues does not affect the functionality of the extension in any way.

Steps to reproduce:

1. Load the latest Alpha Build V2 Chromium extension in the Chromium browser
2. Perform the steps from the “Native Messaging Changes” section for the Alpha Build V2 extension from https://github.com/mozilla-extensions/firefox-bridge/releases to install the native messaging host so that Firefox will be detected by the Chromium extension.
3. Reload the welcome page on the Chromium browsers
4. Notice the page layout breaks for a short period of time
5. Notice that several errors are logged to the extension console. See attached screenshot.

Expected:
Reloading the welcome page should not break the page’s layout one Firefox is detected as installed.

Actual:
The welcome page layout gets broken upon reloading the page, after Firefox is detected as installed.

Welcome page layout issues upon page reload after Firefox is detected as installed:

Errors in Chromium extension console: