Add OS X implementation of wxAppProgressIndicator.

Closes #16638.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78499 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gauge.h

@@ -42,6 +42,8 @@
 
 extern WXDLLIMPEXP_DATA_CORE(const char) wxGaugeNameStr[];
 
+class WXDLLIMPEXP_FWD_CORE wxAppProgressIndicator;
+
 // ----------------------------------------------------------------------------
 // wxGauge: a progress bar
 // ----------------------------------------------------------------------------
@@ -99,6 +101,8 @@ protected:
     int m_nDirection;       // can be wxRIGHT or wxLEFT
 #endif
 
+    wxAppProgressIndicator *m_appProgressIndicator;
+
     wxDECLARE_NO_COPY_CLASS(wxGaugeBase);
 };