Allow the default browser check to return "unknown" and reflect that in the UI.

chrome/browser/gtk/options/general_page_gtk.cc

 // Copyright (c) 2006-2009 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/gtk/options/general_page_gtk.h"
 
 #include "app/l10n_util.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/gtk/keyword_editor_view.h"
@@ skipping 675 matching lines @@
       enable &&
       gtk_tree_selection_count_selected_rows(startup_custom_pages_selection_));
   gtk_widget_set_sensitive(startup_use_current_page_button_, enable);
   gtk_widget_set_sensitive(startup_custom_pages_tree_, enable);
 }
 
 void GeneralPageGtk::SetDefaultBrowserUIState(
     ShellIntegration::DefaultBrowserUIState state) {
   const char* color = NULL;
   std::string text;
-  if (state == ShellIntegration::STATE_DEFAULT) {
+  if (state == ShellIntegration::STATE_IS_DEFAULT) {
     color = kDefaultBrowserLabelColor;
     text = l10n_util::GetStringFUTF8(IDS_OPTIONS_DEFAULTBROWSER_DEFAULT,
         l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
   } else if (state == ShellIntegration::STATE_NOT_DEFAULT) {
     color = kNotDefaultBrowserLabelColor;
     text = l10n_util::GetStringFUTF8(IDS_OPTIONS_DEFAULTBROWSER_NOTDEFAULT,
         l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
+  } else if (state == ShellIntegration::STATE_UNKNOWN) {
+    color = kNotDefaultBrowserLabelColor;
+    text = l10n_util::GetStringFUTF8(IDS_OPTIONS_DEFAULTBROWSER_UNKNOWN,
+        l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
   }
   if (color) {
     char* markup = g_markup_printf_escaped(kDefaultBrowserLabelMarkup,
                                            color, text.c_str());
     gtk_label_set_markup(GTK_LABEL(default_browser_status_label_), markup);
     g_free(markup);
   }
 
   gtk_widget_set_sensitive(default_browser_use_as_default_button_,
                            state == ShellIntegration::STATE_NOT_DEFAULT);
 }