Creating supervised users restricted for regular users if they are supervised.

chrome/browser/chromeos/login/users/chrome_user_manager.cc

 // Copyright 2014 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/chromeos/login/users/chrome_user_manager.h"
 #include "components/user_manager/user_manager.h"
 
 namespace chromeos {
 
 ChromeUserManager::ChromeUserManager(
     scoped_refptr<base::TaskRunner> task_runner,
     scoped_refptr<base::TaskRunner> blocking_task_runner)
     : UserManagerBase(task_runner, blocking_task_runner) {
 }
 
 ChromeUserManager::~ChromeUserManager() {
 }
 
 // static
 ChromeUserManager* ChromeUserManager::Get() {
   user_manager::UserManager* user_manager = user_manager::UserManager::Get();
   return user_manager ? static_cast<ChromeUserManager*>(user_manager) : NULL;
 }
 
+// static
+user_manager::UserList ChromeUserManager::GetUsersAllowedAsSUManagers(
+    const user_manager::UserList& user_list) {
+  user_manager::UserList result;
+  for (user_manager::User* user : user_list) {
+    if (user->GetType() == user_manager::USER_TYPE_REGULAR) {

[Nikita (slow), 2014/11/12 11:09:08]

nit: merge with https://codereview.chromium.org/718673002/, 
may use here
if (user->IsRegular() && !user->IsSupervised())

[merkulova, 2014/11/12 13:19:51]

Why not simply leave this check?

[Nikita (slow), 2014/11/12 13:43:37]

I think that this condition (user->IsRegular() && !user->IsSupervised()) is more
self-descriptive.

Looking at (user->GetType() == user_manager::USER_TYPE_REGULAR) one can easily
forget that there's also USER_TYPE_REGULAR_SUPERVISED.

Plus condition that I propose is shorter and doesn't expose enum value which
should be avoid if possible.

+      result.push_back(user);
+    }
+  }
+  return result;
+}
+
 }  // namespace chromeos