Add wxTEST_DIALOG for testing of modal dialogs.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72837 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/dlgcmn.cpp

@@ -43,6 +43,7 @@
 #include "wx/bookctrl.h"
 #include "wx/scrolwin.h"
 #include "wx/textwrapper.h"
+#include "wx/testing.h"
 
 #if wxUSE_DISPLAY
 #include "wx/display.h"
@@ -50,6 +51,8 @@
 
 extern WXDLLEXPORT_DATA(const char) wxDialogNameStr[] = "dialog";
 
+wxModalDialogHook *wxModalDialogHook::ms_instance = NULL;
+
 // ----------------------------------------------------------------------------
 // XTI
 // ----------------------------------------------------------------------------