implement DoGetBsetSize() for wxNoteBook (patch 745533)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@20880 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/notebook.h

@@ -161,6 +161,10 @@ public:
     }
 
 protected:
+    // calculate the best size of the notebook as the max of the best sizes of
+    // its pages
+    virtual wxSize DoGetBestSize() const;
+
     // remove the page and return a pointer to it
     virtual wxNotebookPage *DoRemovePage(int page);