content clipping becomes a runtime attribute

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@33210 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/laywin.cpp

@@ -54,6 +54,9 @@ void wxSashLayoutWindow::Init()
 {
     m_orientation = wxLAYOUT_HORIZONTAL;
     m_alignment = wxLAYOUT_TOP;
+#ifdef __WXMAC__
+    MacSetClipChildren( true ) ;
+#endif
 }
 
 // This is the function that wxLayoutAlgorithm calls to ascertain the window