bug#48307: Feature request: provide default keybindings to change the font size in all windows

[Eli Zaretskii]

> Date: Mon, 10 May 2021 14:24:35 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: cpitclaudel@gmail.com, 48307@debbugs.gnu.org
> 
> The patch I just sent avoids that problem, and does what other programs do 
> when the user zooms: their frames are not resized.

I think it's a mistake.  Other programs don't change all the fonts on
display, only the one in the main window, which is more similar to
text-scale-adjust.  This feature was supposed to change _everything_,
which is why it modifies the default face.