high-dpi gnome support based on settings

[braydonf]

It looks like it's possible with v0.16 to use chromium args to set a scaling factor:

"chromium-args": "--force-device-scale-factor=1.5"

However, it would be useful to be able to have the scaling factor determined by the desktop gsettings.

Reference implementation that is doing something similar:
electron/electron#727

[ghostoy]

I'll look into this issue.

[ghostoy]

@braydonf NW.js used Xtf.dpi for detecting the scaling factor under Linux. If you have HiDPI display, Xtf.dpi should be set to a number greater than 96 by the system. Then NW.js will use (Xtf.dpi / 96) as the scaling factor by default.

[braydonf]

Actually, it looks like this is working in v0.16 and is changing based on system settings from the scaling setting in "Displays" -> "Scale for menu and title bars", as the Xtf.dpi changes from that setting.

xrdb -query | grep dpi