Fix theme install crasher....

chrome/browser/extensions/theme_installed_infobar_delegate.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/theme_installed_infobar_delegate.h"
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/string_util.h"
 #include "chrome/browser/extensions/extensions_service.h"
@@ skipping 51 matching lines @@
   return BUTTON_CANCEL;
 }
 
 std::wstring ThemeInstalledInfoBarDelegate::GetButtonLabel(
     ConfirmInfoBarDelegate::InfoBarButton button) const {
   switch (button) {
     case BUTTON_CANCEL: {
       return l10n_util::GetString(IDS_THEME_INSTALL_INFOBAR_UNDO_BUTTON);
     }
     default:
-      NOTREACHED();
+      // The InfoBar will create a default OK button and make it invisible.
+      // TODO(mirandac): remove the default OK button from ConfirmInfoBar.
       return L"";
   }
 }
 
 bool ThemeInstalledInfoBarDelegate::Cancel() {
   was_canceled_ = true;
   if (!previous_theme_id_.empty()) {
     ExtensionsService* service = profile_->GetExtensionsService();
     if (service) {
       Extension* previous_theme = service->GetExtensionById(previous_theme_id_);
       if (previous_theme) {
         profile_->SetTheme(previous_theme);
         return true;
       }
     }
   }
 
   profile_->ClearTheme();
   return true;
 }