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 20 matching lines @@
   // Infobars.
   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)) {
+  for (InfoBars::const_iterator i(infobars_.begin()); i != infobars_.end();
+       ++i) {
+    if ((*i)->EqualsDelegate(delegate)) {
+      DCHECK_NE(*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 15 matching lines @@
   RemoveInfoBarInternal(delegate, true);
 }
 
 void InfoBarTabHelper::ReplaceInfoBar(InfoBarDelegate* old_delegate,
                                       InfoBarDelegate* new_delegate) {
   if (!infobars_enabled_) {
     AddInfoBar(new_delegate);  // Deletes the delegate.
     return;
   }
 
-  size_t i;
-  for (i = 0; i < infobars_.size(); ++i) {
-    if (GetInfoBarDelegateAt(i) == old_delegate)
-      break;
-  }
-  DCHECK_LT(i, infobars_.size());
+  InfoBars::iterator i(std::find(infobars_.begin(), infobars_.end(),
+                                 old_delegate));
+  DCHECK(i != infobars_.end());
 
-  infobars_.insert(infobars_.begin() + i, new_delegate);
+  i = infobars_.insert(i, new_delegate) + 1;
   // Remove the old delegate before notifying, so that if any observers call
   // back to AddInfoBar() or similar, we don't dupe-check against this delegate.
-  infobars_.erase(infobars_.begin() + i + 1);
+  infobars_.erase(i);
 
   old_delegate->clear_owner();
   InfoBarReplacedDetails replaced_details(old_delegate, new_delegate);
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REPLACED,
       content::Source<InfoBarTabHelper>(this),
       content::Details<InfoBarReplacedDetails>(&replaced_details));
 }
 
 InfoBarDelegate* InfoBarTabHelper::GetInfoBarDelegateAt(size_t index) {
   return infobars_[index];
 }
 
 void InfoBarTabHelper::RemoveInfoBarInternal(InfoBarDelegate* delegate,
                                              bool animate) {
   if (!infobars_enabled_) {
     DCHECK(infobars_.empty());
     return;
   }
 
-  size_t i;
-  for (i = 0; i < infobars_.size(); ++i) {
-    if (GetInfoBarDelegateAt(i) == delegate)
-      break;
-  }
-  DCHECK_LT(i, infobars_.size());
-  InfoBarDelegate* infobar = infobars_[i];
+  InfoBars::iterator i(std::find(infobars_.begin(), infobars_.end(), delegate));
+  DCHECK(i != infobars_.end());
 
-  infobar->clear_owner();
+  delegate->clear_owner();
   // Remove the delegate before notifying, so that if any observers call back to
   // AddInfoBar() or similar, we don't dupe-check against this delegate.
-  infobars_.erase(infobars_.begin() + i);
+  infobars_.erase(i);
   // Remove ourselves as an observer if we are tracking no more InfoBars.
   if (infobars_.empty()) {
     registrar_.Remove(
         this, content::NOTIFICATION_NAV_ENTRY_COMMITTED,
         content::Source<NavigationController>(
             &web_contents()->GetController()));
   }
 
-  InfoBarRemovedDetails removed_details(infobar, animate);
+  InfoBarRemovedDetails removed_details(delegate, animate);
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_TAB_CONTENTS_INFOBAR_REMOVED,
       content::Source<InfoBarTabHelper>(this),
       content::Details<InfoBarRemovedDetails>(&removed_details));
 }
 
 void InfoBarTabHelper::RemoveAllInfoBars(bool animate) {
   while (!infobars_.empty())
     RemoveInfoBarInternal(GetInfoBarDelegateAt(infobar_count() - 1), animate);
 }
@@ skipping 60 matching lines @@
         if (delegate->ShouldExpire(committed_details))
           RemoveInfoBar(delegate);
       }
 
       break;
     }
     default:
       NOTREACHED();
   }
 }