Make sure to display an errors that occur during the chrome sign in process

chrome/common/pref_names.h

 // 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.
 
 // Constants for the names of various preferences, for easier changing.
 
 #ifndef CHROME_COMMON_PREF_NAMES_H_
 #define CHROME_COMMON_PREF_NAMES_H_
 
 #include <stddef.h>
@@ skipping 589 matching lines @@
 extern const char kSyncSessionsGUID[];
 
 extern const char kInvalidatorInvalidationState[];
 extern const char kInvalidatorMaxInvalidationVersions[];
 
 extern const char kSyncPromoStartupCount[];
 extern const char kSyncPromoViewCount[];
 extern const char kSyncPromoUserSkipped[];
 extern const char kSyncPromoShowOnFirstRunAllowed[];
 extern const char kSyncPromoShowNTPBubble[];
+extern const char kSyncPromoErrorMessage[];
 
 extern const char kProfileGAIAInfoUpdateTime[];
 extern const char kProfileGAIAInfoPictureURL[];
 
 extern const char kWebAppCreateOnDesktop[];
 extern const char kWebAppCreateInAppsMenu[];
 extern const char kWebAppCreateInQuickLaunchBar[];
 
 extern const char kGeolocationAccessToken[];
 #if defined(OS_ANDROID)
@@ skipping 175 matching lines @@
 extern const char kInManagedMode[];
 
 extern const char kNetworkProfileWarningsLeft[];
 extern const char kNetworkProfileLastWarningTime[];
 
 extern const char kLastPolicyStatisticsUpdate[];
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_