cros: Use SessionController to enable system tray settings / notifications tray

ash/system/tray/system_tray_delegate.cc

 // 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.
 
 #include "ash/system/tray/system_tray_delegate.h"
 
 #include "ash/system/tray/ime_info.h"
 #include "ash/system/tray/system_tray_item.h"
 
 namespace ash {
@@ skipping 33 matching lines @@
 }
 
 bool SystemTrayDelegate::IsUserSupervised() const {
   return false;
 }
 
 bool SystemTrayDelegate::IsUserChild() const {
   return false;
 }
 
-bool SystemTrayDelegate::ShouldShowSettings() const {
-  return false;
-}
-
-bool SystemTrayDelegate::ShouldShowNotificationTray() const {
-  return false;
-}
-
 void SystemTrayDelegate::ShowEnterpriseInfo() {}
 
 void SystemTrayDelegate::ShowUserLogin() {}
 
 void SystemTrayDelegate::GetCurrentIME(IMEInfo* info) {}
 
 void SystemTrayDelegate::GetAvailableIMEList(IMEInfoList* list) {}
 
 void SystemTrayDelegate::GetCurrentIMEProperties(IMEPropertyInfoList* list) {}
 
@@ skipping 31 matching lines @@
 
 void SystemTrayDelegate::RemoveCustodianInfoTrayObserver(
     CustodianInfoTrayObserver* observer) {}
 
 std::unique_ptr<SystemTrayItem> SystemTrayDelegate::CreateRotationLockTrayItem(
     SystemTray* tray) {
   return nullptr;
 }
 
 }  // namespace ash