Offscreen QPA: implement a native interface

Many code paths simply expect to have a native interface
available, and won't check if a plugin is returning nullptr
for it. This leads to crashes or local workarounds
(e.g. 3197932e6fb03fb9c0ff669af858cb94e3836d79). Instead,
have offscreen implement a dummy native interface.

This requires shuffling some code for the X11 integration.

Change-Id: I2bdceee379e4ded9b085ebbb4d03d1e074f60726
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit ecd11e498f18a18a79a062c39c0917439479ae4d)

0 files changed, 0 insertions, 0 deletions