Fixes bug where tooltips would get stuck. This was happening because...

chrome/views/aero_tooltip_manager.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_VIEWS_AERO_TOOLTIP_MANAGER_H__
 #define CHROME_VIEWS_AERO_TOOLTIP_MANAGER_H__
 
 #include "base/ref_counted.h"
 #include "base/task.h"
 #include "chrome/views/tooltip_manager.h"
@@ skipping 13 matching lines @@
 //
 //  So instead, we have to partially implement tooltips ourselves using
 //  TTF_TRACKed tooltips.
 //
 // TODO(glen): Resolve this with Microsoft.
 class AeroTooltipManager : public TooltipManager {
  public:
   AeroTooltipManager(Container* container, HWND parent);
   virtual ~AeroTooltipManager();
 
-  void OnMouse(UINT u_msg, WPARAM w_param, LPARAM l_param);
+  virtual void OnMouse(UINT u_msg, WPARAM w_param, LPARAM l_param);
+  virtual void OnMouseLeave();
 
  private:
   void Init();
   void OnTimer();
 
   class InitialTimer : public base::RefCounted<InitialTimer> {
    public:
     InitialTimer(AeroTooltipManager* manager, int time);
     void Disown();
     void Execute();
 
    private:
     AeroTooltipManager* manager_;
   };
 
   int initial_delay_;
   scoped_refptr<InitialTimer> initial_timer_;
 };
 
 }  // namespace views
 
 #endif  // #ifndef CHROME_VIEWS_AERO_TOOLTIP_MANAGER_H__