wxWindow::SetWindowVariant() does do something under ports other than wxOSX.

Document that this function adjusts the window font size under non-OS X
systems and explain why it should still be used instead of changing the font
size directly.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75632 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/window.h

@@ -2911,12 +2911,17 @@ public:
     virtual void SetName(const wxString& name);
 
     /**
-        This function can be called under all platforms but only does anything under
-        Mac OS X 10.3+ currently. Under this system, each of the standard control can
-        exist in several sizes which correspond to the elements of wxWindowVariant enum.
+        Chooses a different variant of the window display to use.
 
-        By default the controls use the normal size, of course, but this function can
-        be used to change this.
+        Window variants currently just differ in size, as can be seen from
+        ::wxWindowVariant documentation. Under all platforms but OS X, this
+        function does nothing more than change the font used by the window.
+        However under OS X it is implemented natively and selects the
+        appropriate variant of the native widget, which has better appearance
+        than just scaled down or up version of the normal variant, so it should
+        be preferred to directly tweaking the font size.
+
+        By default the controls naturally use the normal variant.
     */
     void SetWindowVariant(wxWindowVariant variant);