Make sure auth error reporting handles guest mode correctly.

chrome/browser/profiles/profiles_state.h

 // Copyright 2013 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.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILES_STATE_H_
 #define CHROME_BROWSER_PROFILES_PROFILES_STATE_H_
 
 #include <vector>
 #include "base/strings/string16.h"
 
 class Browser;
 class PrefRegistrySimple;
 class Profile;
+class SigninErrorController;
 namespace base { class FilePath; }
 
 namespace profiles {
 
 // Checks if multiple profiles is enabled.
 bool IsMultipleProfilesEnabled();
 
 // Returns the path to the default profile directory, based on the given
 // user data directory.
 base::FilePath GetDefaultProfileDir(const base::FilePath& user_data_dir);
@@ skipping 21 matching lines @@
 
 // Returns whether the |browser|'s profile is a non-incognito or guest profile.
 // The distinction is needed because guest profiles are implemented as
 // incognito profiles.
 bool IsRegularOrGuestSession(Browser* browser);
 
 // If the --google-profile-info flag is turned on, starts an update for a new
 // version of the Gaia profile picture.
 void UpdateGaiaProfilePhotoIfNeeded(Profile* profile);
 
+// Returns the sign-in error controller for the given profile.  Some profiles,
+// like guest profiles, may not have a controller so this function may return
+// NULL.
+SigninErrorController* GetSigninErrorController(Profile* profile);
+
 }  // namespace profiles
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILES_STATE_H_