cros: Disable system tray help/lock buttons during supervised user creation

ash/test/test_session_controller_client.cc

 // Copyright 2017 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 "ash/test/test_session_controller_client.h"
 
 #include <algorithm>
 #include <string>
 
 #include "ash/login_status.h"
@@ skipping 78 matching lines @@
   for (int numbered_user_index = 0; numbered_user_index < count;
        ++numbered_user_index) {
     AddUserSession(base::StringPrintf("user%d@tray", numbered_user_index));
   }
 
   // Updates session state after adding user sessions.
   SetSessionState(session_manager::SessionState::ACTIVE);
 }
 
 void TestSessionControllerClient::AddUserSession(
-    const std::string& display_email) {
+    const std::string& display_email,
+    bool enable_settings) {
   mojom::UserSessionPtr session = mojom::UserSession::New();
   session->session_id = ++fake_session_id_;
   session->type = user_manager::USER_TYPE_REGULAR;
   session->account_id =
       AccountId::FromUserEmail(GetUserIdFromEmail(display_email));
   session->display_name = "Über tray Über tray Über tray Über tray";
   session->display_email = display_email;
-  session->should_enable_settings = true;
+  session->should_enable_settings = enable_settings;
   session->should_show_notification_tray = true;
   controller_->UpdateUserSession(std::move(session));
 }
 
 void TestSessionControllerClient::UnlockScreen() {
   SetSessionState(session_manager::SessionState::ACTIVE);
 }
 
 void TestSessionControllerClient::RequestLockScreen() {
   SetSessionState(session_manager::SessionState::LOCKED);
@@ skipping 51 matching lines @@
   if (it == sessions.end()) {
     NOTREACHED();
     return;
   }
 
   SwitchActiveUser((*it)->account_id);
 }
 
 }  // namespace test
 }  // namespace ash