The User Manager should be backed by a special profile, not the guest one.

chrome/browser/profiles/profile_window.cc

 // 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.
 
 #include "chrome/browser/profiles/profile_window.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 104 matching lines @@
   // Passing true for |always_create| means we won't duplicate the code that
   // tries to find a browser.
   profiles::FindOrCreateNewWindowForProfile(
       profile,
       is_process_startup,
       is_first_run,
       desktop_type,
       true);
 }
 
-// Called after a |guest_profile| is available to be used by the user manager.
+// Called after a |profile| is available to be used by the user manager.
 // Based on the value of |tutorial_mode| we determine a url to be displayed
 // by the webui and run the |callback|, if it exists.
-void OnUserManagerGuestProfileCreated(
+void OnUserManagerProfileCreated(
     const base::FilePath& profile_path_to_focus,
     profiles::UserManagerTutorialMode tutorial_mode,
     const base::Callback<void(Profile*, const std::string&)>& callback,
-    Profile* guest_profile,
+    Profile* profile,
     Profile::CreateStatus status) {
   if (status != Profile::CREATE_STATUS_INITIALIZED || callback.is_null())
     return;
 
   // Tell the webui which user should be focused.
   std::string page = chrome::kChromeUIUserManagerURL;
 
   if (tutorial_mode == profiles::USER_MANAGER_TUTORIAL_OVERVIEW) {
     page += "#tutorial";
   } else if (!profile_path_to_focus.empty()) {
     const ProfileInfoCache& cache =
         g_browser_process->profile_manager()->GetProfileInfoCache();
     size_t index = cache.GetIndexOfProfileWithPath(profile_path_to_focus);
     if (index != std::string::npos) {
       page += "#";
       page += base::IntToString(index);
     }
   }
 
-  callback.Run(guest_profile, page);
+  callback.Run(profile, page);
 }
 
 }  // namespace
 
 namespace profiles {
 
 void FindOrCreateNewWindowForProfile(
     Profile* profile,
     chrome::startup::IsProcessStartup process_startup,
     chrome::startup::IsFirstRun is_first_run,
@@ skipping 83 matching lines @@
   DCHECK(profile);
   ProfileInfoCache& cache =
       g_browser_process->profile_manager()->GetProfileInfoCache();
 
   size_t index = cache.GetIndexOfProfileWithPath(profile->GetPath());
   cache.SetProfileSigninRequiredAtIndex(index, true);
   chrome::ShowUserManager(profile->GetPath());
   BrowserList::CloseAllBrowsersWithProfile(profile);
 }
 
-void CreateGuestProfileForUserManager(
+void CreateUserManagerProfile(
     const base::FilePath& profile_path_to_focus,
     profiles::UserManagerTutorialMode tutorial_mode,
     const base::Callback<void(Profile*, const std::string&)>& callback) {
   // Create the guest profile, if necessary, and open the User Manager
   // from the guest profile.
   g_browser_process->profile_manager()->CreateProfileAsync(
-      ProfileManager::GetGuestProfilePath(),
-      base::Bind(&OnUserManagerGuestProfileCreated,
+      ProfileManager::GetUserManagerProfilePath(),
+      base::Bind(&OnUserManagerProfileCreated,
                  profile_path_to_focus,
                  tutorial_mode,
                  callback),
       base::string16(),
       base::string16(),
       std::string());
 }
 
 void ShowUserManagerMaybeWithTutorial(Profile* profile) {
   // Guest users cannot appear in the User Manager, nor display a tutorial.
@@ skipping 10 matching lines @@
 
   if (tutorial_shown) {
     chrome::ShowUserManager(profile->GetPath());
   } else {
     chrome::ShowUserManagerWithTutorial(
         profiles::USER_MANAGER_TUTORIAL_OVERVIEW);
   }
 }
 
 }  // namespace profiles