With the firefox extension enabled, some websites are being rendered before styles have been applied.
Firefox 105.0b9, LastPass for Firefox 4.101.0
To reproduce:
- Open https://github.com (also reproduced on several other websites, although not every one)
- If this isn't sufficient to reproduce it, or to trigger it again, use Ctrl/Cmd+Shift+R to bypass cache and refresh
Expected behaviour:
- Page loads normally, like it does with the LastPass extension disabled
Actual behaviour:
- Page initially renders without any stylesheets, then reflows as the styles get applied
- "Layout was forced before the page was fully loaded. If stylesheets are not yet loaded this may cause a flash of unstyled content." is logged to the dev console, with an origin of moz-extension://2d23e33b-fcbb-42d7-8327-40a3b7c4c9c4/web-client-content-script.js:1:325262
- This points to `a = Object(l.useState) (visualViewport.height),` in the formatted minified code of web-client-content-script.js
This doesn't happen on Chrome, but Chrome does log "[Violation] Forced reflow while executing JavaScript took 31ms", so I think Chrome is just a bit more defensive against this.
This has definitely become more prevalent recently, although I'm not sure exactly when (the last extension update, in early August, seems plausible, though I would have guessed slightly more recent than that).
