Fix a few bugs with the theme infobar:

chrome/browser/extensions/extension_install_ui.cc

 // Copyright (c) 2009 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/extensions/extension_install_ui.h"
 
 #include <map>
 
 #include "app/l10n_util.h"
 #include "base/file_util.h"
@@ skipping 92 matching lines @@
     return;
 
   Browser* browser = BrowserList::GetLastActiveWithProfile(profile_);
   if (!browser)
     return;
 
   TabContents* tab_contents = browser->GetSelectedTabContents();
   if (!tab_contents)
     return;
 
-  // First remove any previous theme preview infobar.
+  // First find any previous theme preview infobars.
+  InfoBarDelegate* old_delegate = NULL;
   for (int i = 0; i < tab_contents->infobar_delegate_count(); ++i) {
     InfoBarDelegate* delegate = tab_contents->GetInfoBarDelegateAt(i);
     if (delegate->AsThemePreviewInfobarDelegate()) {
-      tab_contents->RemoveInfoBar(delegate);
+      old_delegate = delegate;
       break;
     }
   }
 
-  // Now add the new one.
-  tab_contents->AddInfoBar(new ThemePreviewInfobarDelegate(
-      tab_contents, extension->name()));
+  // Then either replace that old one or add a new one.
+  InfoBarDelegate* new_delegate = new ThemePreviewInfobarDelegate(tab_contents,
+      extension->name());
+
+  if (old_delegate)
+    tab_contents->ReplaceInfoBar(old_delegate, new_delegate);
+  else
+    tab_contents->AddInfoBar(new_delegate);
 }