Add a SigninAllowed policy.

chrome/browser/ui/webui/ntp/ntp_login_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/ntp/ntp_login_handler.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 232 matching lines @@
       header_value, sub_header_value, icon_url_value, is_user_signed_in);
 }
 
 // static
 bool NTPLoginHandler::ShouldShow(Profile* profile) {
 #if defined(OS_CHROMEOS)
   // For now we don't care about showing sync status on Chrome OS. The promo
   // UI and the avatar menu don't exist on that platform.
   return false;
 #else
-  return !profile->IsOffTheRecord();
+  return !profile->IsOffTheRecord() &&
+      profile->GetOriginalProfile()->IsSigninAllowed();

[Andrew T Wilson (Slow), 2013/02/04 15:41:48]

Probably don't need to call GetOriginalProfile() here since we know that the
profile is not off the record, but it's fine as-is.

[Adrian Kuegel, 2013/02/05 10:55:15]

True, this is not necessary. I removed it, now it fits in one line.

 #endif
 }
 
 // static
 void NTPLoginHandler::GetLocalizedValues(Profile* profile,
                                          DictionaryValue* values) {
   PrefService* prefs = profile->GetPrefs();
   std::string error_message = prefs->GetString(prefs::kSyncPromoErrorMessage);
   bool hide_sync = !prefs->GetBoolean(prefs::kSyncPromoShowNTPBubble);
 
   string16 message =
       hide_sync ? string16() :
           !error_message.empty() ? UTF8ToUTF16(error_message) :
               l10n_util::GetStringFUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_MESSAGE,
                   l10n_util::GetStringUTF16(IDS_SHORT_PRODUCT_NAME));
 
   values->SetString("login_status_message", message);
   values->SetString("login_status_url",
       hide_sync ? std::string() : chrome::kSyncLearnMoreURL);
   values->SetString("login_status_advanced",
       hide_sync || !error_message.empty() ? string16() :
       l10n_util::GetStringUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_ADVANCED));
   values->SetString("login_status_dismiss",
       hide_sync ? string16() :
       l10n_util::GetStringUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_OK));
 }