Guest mode causes certain settings to be hidden.

chrome/browser/ui/webui/options/startup_pages_handler.cc

Index: chrome/browser/ui/webui/options/startup_pages_handler.cc
diff --git a/chrome/browser/ui/webui/options/startup_pages_handler.cc b/chrome/browser/ui/webui/options/startup_pages_handler.cc
index 7aaf5f1f1597e4583e2a166d88c231d98b71c4d7..6563b45ff4d5305962a607ef9e4c86460bee874e 100644
--- a/chrome/browser/ui/webui/options/startup_pages_handler.cc
+++ b/chrome/browser/ui/webui/options/startup_pages_handler.cc
@@ -48,6 +48,11 @@ void StartupPagesHandler::GetLocalizedValues(
 }
 
 void StartupPagesHandler::RegisterMessages() {
+  // Guest profiles should never have been displayed the option to set these
+  // values.
+  if (Profile::FromWebUI(web_ui())->IsOffTheRecord())
+    return;
+
   web_ui()->RegisterMessageCallback("removeStartupPages",
       base::Bind(&StartupPagesHandler::RemoveStartupPages,
                  base::Unretained(this)));