function bindPre343Styles() {
	whenUIChromeLoaded(() => {
		if (isPreviousMessengerVersion()) {
			const classList = document.querySelector('#facebook').classList;
			if (!classList.contains('goofy343')) {
				classList.add('goofy343');
			}
		}
	});
}
Handling the old messenger.com style (new version of messenger.com was 
released ~May 2019 and slowly rolled out to all users). 

Checks for a CSS class in the pre-May 2019 version and if found, apply 
the old .css for it.