Replace the virtual InfoBarDelegate::InfoBarClosed() function with a non-virtual one. This is a ...

chrome/browser/plugin_installer_infobar_delegate.h

 // Copyright (c) 2011 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_BROWSER_PLUGIN_INSTALLER_INFOBAR_DELEGATE_H_
 #define CHROME_BROWSER_PLUGIN_INSTALLER_INFOBAR_DELEGATE_H_
 #pragma once
 
 #include "chrome/browser/tab_contents/confirm_infobar_delegate.h"
 
 class TabContents;
 
 // The main purpose for this class is to popup/close the infobar when there is
 // a missing plugin.
 class PluginInstallerInfoBarDelegate : public ConfirmInfoBarDelegate {
  public:
   explicit PluginInstallerInfoBarDelegate(TabContents* tab_contents);
 
  private:
   virtual ~PluginInstallerInfoBarDelegate();
 
   // ConfirmInfoBarDelegate:
-  virtual gfx::Image* GetIcon() const;
-  virtual PluginInstallerInfoBarDelegate* AsPluginInstallerInfoBarDelegate();
-  virtual string16 GetMessageText() const;
-  virtual int GetButtons() const;
-  virtual string16 GetButtonLabel(InfoBarButton button) const;
-  virtual bool Accept();
-  virtual string16 GetLinkText();
-  virtual bool LinkClicked(WindowOpenDisposition disposition);
+  virtual gfx::Image* GetIcon() const OVERRIDE;
+  virtual PluginInstallerInfoBarDelegate*
+      AsPluginInstallerInfoBarDelegate() OVERRIDE;
+  virtual string16 GetMessageText() const OVERRIDE;
+  virtual int GetButtons() const OVERRIDE;
+  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual bool Accept() OVERRIDE;
+  virtual string16 GetLinkText() OVERRIDE;
+  virtual bool LinkClicked(WindowOpenDisposition disposition) OVERRIDE;
 
   // The containing TabContents
   TabContents* tab_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInstallerInfoBarDelegate);
 };
 
 #endif  // CHROME_BROWSER_PLUGIN_INSTALLER_INFOBAR_DELEGATE_H_