A few small tweaks based on further analysis of GoogleURLTracker:

chrome/browser/infobars/infobar_tab_helper.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/infobars/infobar_tab_helper.h"
 
 #include "chrome/browser/infobars/infobar.h"
 #include "chrome/browser/infobars/infobar_delegate.h"
 #include "chrome/browser/tab_contents/insecure_content_infobar_delegate.h"
 #include "chrome/common/chrome_notification_types.h"
@@ skipping 21 matching lines @@
   RemoveAllInfoBars(false);
 }
 
 void InfoBarTabHelper::AddInfoBar(InfoBarDelegate* delegate) {
   if (!infobars_enabled_) {
     delegate->InfoBarClosed();
     return;
   }
 
   for (size_t i = 0; i < infobars_.size(); ++i) {
-    if (GetInfoBarDelegateAt(i)->EqualsDelegate(delegate)) {
+    InfoBarDelegate* delegate_at_i = GetInfoBarDelegateAt(i);

[Ilya Sherman, 2012/05/02 03:52:43]

nit: Perhaps use an iterator instead of creating this temporary variable (unless
it's important to use GetInfoBarDelegateAt() here)?

+    if (delegate_at_i->EqualsDelegate(delegate)) {
+      DCHECK_NE(delegate_at_i, delegate);
       delegate->InfoBarClosed();
       return;
     }
   }
 
   // TODO(pkasting): Consider removing InfoBarTabHelper arg from delegate
   // constructors and instead using a setter from here.
   infobars_.push_back(delegate);
   // Add ourselves as an observer for navigations the first time a delegate is
   // added. We use this notification to expire InfoBars that need to expire on
@@ skipping 147 matching lines @@
         if (delegate->ShouldExpire(committed_details))
           RemoveInfoBar(delegate);
       }
 
       break;
     }
     default:
       NOTREACHED();
   }
 }