implement wxSYS_DCLICK_MSEC support

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@49354 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/mac/carbon/settings.cpp

@@ -233,6 +233,9 @@ int wxSystemSettingsNative::GetMetric(wxSystemMetric index, wxWindow* WXUNUSED(w
         // TODO: case wxSYS_NETWORK_PRESENT:
         // TODO: case wxSYS_SHOW_SOUNDS:
 
+        case wxSYS_DCLICK_MSEC:
+            return (int)(GetDblTime() * 1000. / 60.);
+
         default:
             // unsupported metric
             break;