Comment 1 for bug 1628630

Following the same argument for removing policy from modify_window() that we applied in revision 347 I think it is modify_window() that shouldn't be interpreting state changes to imply resizing.

Moving that logic to before the call to handle_modify_window() in order to provide suggestions for position and size in the modifications argument will allow shells to customise the result. (We do that for surface creation already.)