wayland: when possible, fill in actual and predicted presentation times
wayland: when possible, fill in actual and predicted presentation times

There is currently no Wayland protocol for providing presentation
timestamps or hints about when drawing will be presented onscreen.
However, by assuming the straightforward algorithm used by the
DRM backend to Weston, we can reverse engineer the right values.

https://bugzilla.gnome.org/show_bug.cgi?id=698864

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