[gtk/wip/nacho/quartz-scale-factor] quartz/display: add back scaling factor

[Ignacio Casal Quinteiro <icq src gnome org>]

commit cae6dbde0bf172450519f94826fb6d155fd9404c
Author: Ignacio Casal Quinteiro <qignacio amazon com>
Date:   Tue Dec 18 11:33:16 2018 +0100

    quartz/display: add back scaling factor
    
    With the last patches one thing that got lost if the scaling
    factor. This is very visible when i.e loading a svg image
    in a Retina display.

 gdk/quartz/gdkdisplay-quartz.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/quartz/gdkdisplay-quartz.c b/gdk/quartz/gdkdisplay-quartz.c
index a342b88ff2..490fe0cf37 100644
--- a/gdk/quartz/gdkdisplay-quartz.c
+++ b/gdk/quartz/gdkdisplay-quartz.c
@@ -252,7 +252,7 @@ configure_monitor (GdkMonitor *monitor)
   monitor->width_mm = width;
   monitor->height_mm = height;
   monitor->geometry = disp_geometry;
-  monitor->scale_factor = 1;
+  monitor->scale_factor = CGDisplayModeGetPixelWidth (mode) / (float)CGDisplayModeGetWidth (mode);
   monitor->refresh_rate = refresh_rate;
   monitor->subpixel_layout = GDK_SUBPIXEL_LAYOUT_UNKNOWN;
   CGDisplayModeRelease (mode);