fixed "missing" initial resize of wxMDIChildFrame

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_2_BRANCH@7630 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/window.h

@@ -161,6 +161,10 @@ public:
     wxWindow* GetWindowChild1(wxWindowID id);
     wxWindow* GetWindowChild(wxWindowID id);
 
+    // a MSW only function which sends a size event to the window using its
+    // current size - this has an effect of refreshing the window layout
+    void SendSizeEvent();
+
     // implementation from now on
     // --------------------------