For Wayland outputs, we do not expose the actual transformation because
mutter does not support wl_surface.set_buffer_transform yet, instead we
swap the logical width and height when the output is rotated.
However, a client wishing to use the physical size would get confused,
so if the output is rotated, rotate the physical dimensions as well for
consistency.
Closes: https://gitlab.gnome.org/GNOME/mutter/issues/369
bda9c359af