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

chrome/browser/views/options/general_page_view.cc

Index: chrome/browser/views/options/general_page_view.cc
===================================================================
--- chrome/browser/views/options/general_page_view.cc	(revision 25499)
+++ chrome/browser/views/options/general_page_view.cc	(working copy)
@@ -646,7 +646,7 @@
     ShellIntegration::DefaultBrowserUIState state) {
   bool button_enabled = state == ShellIntegration::STATE_NOT_DEFAULT;
   default_browser_use_as_default_button_->SetEnabled(button_enabled);
-  if (state == ShellIntegration::STATE_DEFAULT) {
+  if (state == ShellIntegration::STATE_IS_DEFAULT) {
     default_browser_status_label_->SetText(
       l10n_util::GetStringF(IDS_OPTIONS_DEFAULTBROWSER_DEFAULT,
                             l10n_util::GetString(IDS_PRODUCT_NAME)));
@@ -658,6 +658,12 @@
                               l10n_util::GetString(IDS_PRODUCT_NAME)));
     default_browser_status_label_->SetColor(kNotDefaultBrowserLabelColor);
     Layout();
+  } else if (state == ShellIntegration::STATE_UNKNOWN) {
+    default_browser_status_label_->SetText(
+        l10n_util::GetStringF(IDS_OPTIONS_DEFAULTBROWSER_UNKNOWN,
+                              l10n_util::GetString(IDS_PRODUCT_NAME)));
+    default_browser_status_label_->SetColor(kNotDefaultBrowserLabelColor);
+    Layout();
   }
 }