Summary:
Despite plasma frameworks doing it's own scaling with fonts, it's been
requested to use kwin/wayland scaling.
Like DRM, when kscreen is not used, scale value is loaded from a config
file.
Config format is
[HWComposerOutputs][0]
Scale=N
The 0 is to map similarly to DRM and support multi-screen, but with a
screen index
rather than a UUID based on EDID.
Because we don't support multi screen this is always 0 for now.
Test Plan: Ran with the config value unset and with the config value at
Scale=3.
Reviewers: #kwin, romangg
Reviewed By: #kwin, romangg
Subscribers: bshah, romangg, nicolasfella, zzag, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D18810
3dc22d7d88