Guest mode causes certain settings to be hidden.

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

 // Copyright (c) 2012 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/ui/webui/options/startup_pages_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
@@ skipping 30 matching lines @@
     { "startupUseCurrent", IDS_OPTIONS_STARTUP_USE_CURRENT },
     { "startupPagesPlaceholder", IDS_OPTIONS_STARTUP_PAGES_PLACEHOLDER },
   };
 
   RegisterStrings(localized_strings, resources, arraysize(resources));
   RegisterTitle(localized_strings, "startupPagesOverlay",
                 IDS_OPTIONS_STARTUP_PAGES_DIALOG_TITLE);
 }
 
 void StartupPagesHandler::RegisterMessages() {
+  // Guest profiles should never have been displayed the option to set
+  // these values.

[Evan Stade, 2014/08/19 17:49:13]

nit: I don't think this comment is necessary

[Mike Lerman, 2014/08/19 20:34:12]

Acknowledged.

+  if (Profile::FromWebUI(web_ui())->IsOffTheRecord())

[Evan Stade, 2014/08/19 17:49:13]

would it be possible to not even create the StartupPagesHandler in the OTR case?

[Mike Lerman, 2014/08/19 20:34:12]

Done, removed this call here and added a check in options_ui.

+    return;
+
   web_ui()->RegisterMessageCallback("removeStartupPages",
       base::Bind(&StartupPagesHandler::RemoveStartupPages,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("addStartupPage",
       base::Bind(&StartupPagesHandler::AddStartupPage,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("editStartupPage",
       base::Bind(&StartupPagesHandler::EditStartupPage,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("setStartupPagesToCurrentPages",
@@ skipping 185 matching lines @@
 
 void StartupPagesHandler::OnResultChanged(bool default_match_changed) {
   const AutocompleteResult& result = autocomplete_controller_->result();
   base::ListValue suggestions;
   OptionsUI::ProcessAutocompleteSuggestions(result, &suggestions);
   web_ui()->CallJavascriptFunction(
       "StartupOverlay.updateAutocompleteSuggestions", suggestions);
 }
 
 }  // namespace options