Fixed a rare wxAuiFloatingFrame dtor crash on MSW using a registration mechanism in wxAuiManager.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51324 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/aui/floatpane.h

@@ -31,6 +31,8 @@
 
 class WXDLLIMPEXP_AUI wxAuiFloatingFrame : public wxAuiFloatingFrameBaseClass
 {
+    friend class wxAuiManager;
+
 public:
     wxAuiFloatingFrame(wxWindow* parent,
                    wxAuiManager* owner_mgr,
@@ -45,6 +47,7 @@ public:
     wxAuiManager* GetOwnerManager() const;
     
 protected:
+    void SetOwnerManager(wxAuiManager* owner_mgr);
     virtual void OnMoveStart();
     virtual void OnMoving(const wxRect& window_rect, wxDirection dir);
     virtual void OnMoveFinished();