Added wxDC::CreateGraphicsContext and implemented it for a few DCs

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@53344 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/dcmemory.h

@@ -22,6 +22,10 @@ public:
     wxMemoryDCImpl( wxMemoryDC *owner, wxBitmap& bitmap );
     wxMemoryDCImpl( wxMemoryDC *owner, wxDC *dc ); // Create compatible DC
 
+#if wxUSE_GRAPHICS_CONTEXT
+    virtual wxGraphicsContext* CreateGraphicsContext();
+#endif
+
     // override some base class virtuals
     virtual void DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
     virtual void DoGetSize(int* width, int* height) const;