Recalculate a projected extent.
// Delphi public procedure RecalcProjectedExtent; virtual;
// C++ Builder public: virtual void RecalcProjectedExtent(void);
Calculation is only an estimation based on 72x36 grid. The grid is necessary because any point from an extent can be moved the after projection to, in fact, any location. Grid size was selected because it will be no more than 5x5 degree.