bug#7342: face remap per frame, not buffer

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Thu, 21 Oct 2021 12:44:11 -0700
> Cc: Peter Dyballa <Peter_Dyballa@freenet.de>, 7342@debbugs.gnu.org
> 
> I think this is working as designed: `text-scale-adjust' works per
> buffer, not per window or frame.
> 
> If you want a different font size in a different window, I recommend using
> `clone-indirect-buffer' or `clone-indirect-buffer-other-window'.
> 
> If you want a different font size in a different frame, you should
> change the font parameters for that frame, see Info node `(elisp) Frame
> Parameters'.

Btw, since this bug was filed, Emacs learned to have window-specific
faces, so the situation is nowadays even better.