Don't enforce signin for the settings app.

chrome/browser/ui/extensions/application_launch.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/extensions/application_launch.h"
 
 #include <string>
 
 #include "apps/launcher.h"
 #include "base/command_line.h"
@@ skipping 327 matching lines @@
       "Extensions.AppLaunchContainer", params.container, 100);
 
   if (extension->is_platform_app()) {
     // Remember what desktop the launch happened on so that when the app opens a
     // window we can open them on the right desktop.
     PerAppSettingsServiceFactory::GetForBrowserContext(profile)->
         SetDesktopLastLaunchedFrom(extension->id(), params.desktop_type);
 #if !defined(OS_CHROMEOS)
     SigninManager* signin_manager =
         SigninManagerFactory::GetForProfile(profile);
-    if (signin_manager && signin_manager->GetAuthenticatedUsername().empty()) {
+    if (extension->id() != extension_misc::kSettingsAppId &&
+        signin_manager && signin_manager->GetAuthenticatedUsername().empty()) {
       const char kEnforceSigninToUseAppsFieldTrial[] = "EnforceSigninToUseApps";
 
       std::string field_trial_value =
           base::FieldTrialList::FindFullName(kEnforceSigninToUseAppsFieldTrial);
 
       // Only enforce signin if the field trial is set.
       if (!field_trial_value.empty()) {
         GURL gurl(l10n_util::GetStringFUTF8(
             IDS_APP_LAUNCH_NOT_SIGNED_IN_LINK,
             base::UTF8ToUTF16(extension->id())));
@@ skipping 138 matching lines @@
   // up in LoadingStateChanged to schedule a GetApplicationInfo. And when
   // the web app info is available, extensions::TabHelper notifies Browser via
   // OnDidGetApplicationInfo, which calls
   // web_app::UpdateShortcutForTabContents when it sees UPDATE_SHORTCUT as
   // pending web app action.
   extensions::TabHelper::FromWebContents(tab)->set_pending_web_app_action(
       extensions::TabHelper::UPDATE_SHORTCUT);
 
   return tab;
 }