Revert of Remove some pre-md code and assets.

ash/common/system/tray/system_tray.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/common/system/tray/system_tray.h"
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
 #include "ash/common/key_event_watcher.h"
 #include "ash/common/login_status.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/session/session_controller.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/system/chromeos/audio/tray_audio.h"
 #include "ash/common/system/chromeos/bluetooth/tray_bluetooth.h"
 #include "ash/common/system/chromeos/brightness/tray_brightness.h"
 #include "ash/common/system/chromeos/cast/tray_cast.h"
 #include "ash/common/system/chromeos/enterprise/tray_enterprise.h"
 #include "ash/common/system/chromeos/media_security/multi_profile_media_tray_item.h"
 #include "ash/common/system/chromeos/network/tray_network.h"
 #include "ash/common/system/chromeos/network/tray_vpn.h"
 #include "ash/common/system/chromeos/power/power_status.h"
 #include "ash/common/system/chromeos/power/tray_power.h"
 #include "ash/common/system/chromeos/screen_security/screen_capture_tray_item.h"
 #include "ash/common/system/chromeos/screen_security/screen_share_tray_item.h"
 #include "ash/common/system/chromeos/session/tray_session_length_limit.h"
+#include "ash/common/system/chromeos/settings/tray_settings.h"
 #include "ash/common/system/chromeos/supervised/tray_supervised_user.h"
 #include "ash/common/system/chromeos/tray_caps_lock.h"
 #include "ash/common/system/chromeos/tray_tracing.h"
 #include "ash/common/system/date/tray_date.h"
 #include "ash/common/system/date/tray_system_info.h"
 #include "ash/common/system/ime/tray_ime_chromeos.h"
 #include "ash/common/system/tiles/tray_tiles.h"
 #include "ash/common/system/tray/system_tray_controller.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_item.h"
@@ skipping 261 matching lines @@
   tray_audio_ = new TrayAudio(this);
   AddTrayItem(base::WrapUnique(tray_audio_));
   AddTrayItem(base::MakeUnique<TrayBrightness>(this));
   AddTrayItem(base::MakeUnique<TrayCapsLock>(this));
   // TODO(jamescook): Remove this when mus has support for display management
   // and we have a DisplayManager equivalent. See http://crbug.com/548429
   std::unique_ptr<SystemTrayItem> tray_rotation_lock =
       delegate->CreateRotationLockTrayItem(this);
   if (tray_rotation_lock)
     AddTrayItem(std::move(tray_rotation_lock));
+  if (!use_md)
+    AddTrayItem(base::MakeUnique<TraySettings>(this));
   AddTrayItem(base::WrapUnique(tray_update_));
   if (use_md) {
     tray_tiles_ = new TrayTiles(this);
     AddTrayItem(base::WrapUnique(tray_tiles_));
     tray_system_info_ = new TraySystemInfo(this);
     AddTrayItem(base::WrapUnique(tray_system_info_));
     // Leading padding.
     AddTrayItem(base::MakeUnique<PaddingTrayItem>());
   } else {
     AddTrayItem(base::WrapUnique(tray_date_));
@@ skipping 456 matching lines @@
           .work_area()
           .height();
   if (work_area_height > 0) {
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Ash.SystemMenu.PercentageOfWorkAreaHeightCoveredByMenu",
         100 * bubble_view->height() / work_area_height, 1, 300, 100);
   }
 }
 
 }  // namespace ash