I have a Chromebook Pixel 2, which has a HiDPI screen. My external monitor has the same resolution in width, but only about half the pixel density. I use Gnome's scaling settings to make things look right, but that only works well when using a single monitor.
Is it possible to scale my laptop display so that its effective resolution is half of the native resolution, but it still fills the screen? I've tried
xrandr --scale 0.5x0.5, but that just seems to shrink the screen without filling the display.