gdk: Make background changes queue a repaint
gdk: Make background changes queue a repaint

For client-side windows, we need to queue a repaint when the background
changes. For native windows, the windowing system does take care of it,
but client-side windows are our own, so we gotta do it manually.

https://bugzilla.gnome.org/show_bug.cgi?id=652102

jadahl/gtk,Lyude/gtk-,ebassi/gtk,grubersjoe/adwaita,jessevdk/gtk,Lyude/gtk-,jadahl/gtk,jessevdk/gtk,jigpu/gtk,ahodesuka/gtk,ahodesuka/gtk,davidgumberg/gtk,jessevdk/gtk,chergert/gtk,bratsche/gtk-,msteinert/gtk,Adamovskiy/gtk,msteinert/gtk,Distrotech/gtk2,jigpu/gtk,alexlarsson/gtk,grubersjoe/adwaita,msteinert/gtk,davidt/gtk,jadahl/gtk,Lyude/gtk-,Sidnioulz/SandboxGtk,chergert/gtk,Sidnioulz/SandboxGtk,Adamovskiy/gtk,msteinert/gtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,jessevdk/gtk,grubersjoe/adwaita,chergert/gtk,ebassi/gtk,ahodesuka/gtk,bratsche/gtk-,jadahl/gtk,jigpu/gtk,ebassi/gtk,chergert/gtk,alexlarsson/gtk,jessevdk/gtk,jadahl/gtk,davidt/gtk,jadahl/gtk,davidgumberg/gtk,alexlarsson/gtk,Adamovskiy/gtk,jigpu/gtk,ahodesuka/gtk,davidgumberg/gtk,Distrotech/gtk2,grubersjoe/adwaita,jigpu/gtk,davidgumberg/gtk,ahodesuka/gtk,ahodesuka/gtk,grubersjoe/adwaita,davidgumberg/gtk,alexlarsson/gtk,chergert/gtk,Sidnioulz/SandboxGtk,chergert/gtk,jigpu/gtk,davidgumberg/gtk,grubersjoe/adwaita,davidt/gtk,Lyude/gtk-,alexlarsson/gtk,Distrotech/gtk2,chergert/gtk,Adamovskiy/gtk,davidt/gtk,davidt/gtk,Distrotech/gtk2,Lyude/gtk-,Adamovskiy/gtk,davidt/gtk,Adamovskiy/gtk,ebassi/gtk,msteinert/gtk,msteinert/gtk,Lyude/gtk-,alexlarsson/gtk,Distrotech/gtk2,ahodesuka/gtk,Adamovskiy/gtk,bratsche/gtk-,alexlarsson/gtk,bratsche/gtk-,Lyude/gtk-,davidgumberg/gtk,Sidnioulz/SandboxGtk,Distrotech/gtk2,Lyude/gtk-,bratsche/gtk-,jessevdk/gtk,jigpu/gtk,grubersjoe/adwaita,Sidnioulz/SandboxGtk,jadahl/gtk,jessevdk/gtk,alexlarsson/gtk,Adamovskiy/gtk,ebassi/gtk,bratsche/gtk-,jadahl/gtk,jigpu/gtk,ahodesuka/gtk,grubersjoe/adwaita,ebassi/gtk,chergert/gtk