use global hwndTT

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3637 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/tooltip.h

@@ -35,6 +35,7 @@ public:
     void RelayEvent(WXMSG *msg);
 
 private:
+    static HWND hwndTT;
     // create the tooltip ctrl for our parent frame if it doesn't exist yet
     // and return its window handle
     WXHWND GetToolTipCtrl();
@@ -45,4 +46,3 @@ private:
     wxString  m_text;           // tooltip text
     wxWindow *m_window;         // window we're associated with
 };
-