window: Store server_allocation in surface size

We used to just store the buffer size here which is not right if the
surface has a buffer_transform or a buffer_scale. To fix this we pass
the transform and scale into the toysurface prepare and swap calls and
move both the surface to buffer and the buffer to surface size
conversion there.

Without this interactive resize on the top or left sides of a transformed
or scaled surface will not work correctly.
1 file changed