Pulled GetDepthBufferSize() out of camera and put it in render window.

graphics/vtkMesaCamera.h

@@ -61,8 +61,6 @@ public:
   // Implement base class method.
   void Render(vtkRenderer *ren);
 
-  int GetDepthBufferSize();
-
 protected:  
   vtkMesaCamera() {};
   ~vtkMesaCamera() {};