Comment 3 for bug 1575191

There's basically nothing we can do about this in Oxide - as Olivier has pointed out, this is a website bug and is specific to the desktop version of Google Plus. Oxide correctly changes the viewport height after the location bar changes position, otherwise elements fixed to the bottom of the viewport would be off the screen when the location bar is shown.

It doesn't happen on Chrome/Android because the location bar in Chrome's tablet UI doesn't hide. That's probably the only way we'd be able to prevent this in Ubuntu.