A few small tweaks based on further analysis of GoogleURLTracker:

chrome/browser/infobars/infobar_tab_helper.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_INFOBARS_INFOBAR_TAB_HELPER_H_
 #define CHROME_BROWSER_INFOBARS_INFOBAR_TAB_HELPER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "content/public/browser/notification_observer.h"
@@ skipping 46 matching lines @@
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // Helper functions for infobars:
   content::WebContents* web_contents() {
     return content::WebContentsObserver::web_contents();
   }
 
  private:
+  typedef std::vector<InfoBarDelegate*> InfoBars;
+
   void RemoveInfoBarInternal(InfoBarDelegate* delegate, bool animate);
   void RemoveAllInfoBars(bool animate);
 
   // Message handlers.
   void OnDidBlockDisplayingInsecureContent();
   void OnDidBlockRunningInsecureContent();
 
   // Delegates for InfoBars associated with this InfoBarTabHelper.
-  std::vector<InfoBarDelegate*> infobars_;
+  InfoBars infobars_;
   bool infobars_enabled_;
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(InfoBarTabHelper);
 };
 
 #endif  // CHROME_BROWSER_INFOBARS_INFOBAR_TAB_HELPER_H_