Inform settings about wxWindow class existence.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@32637 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/settings.h

@@ -15,6 +15,8 @@
 #include "wx/colour.h"
 #include "wx/font.h"
 
+class WXDLLEXPORT wxWindow;
+
 // possible values for wxSystemSettings::GetFont() parameter
 //
 // NB: wxMSW assumes that they have the same values as the parameters of