Hide Night Light behind a flag

ash/system/tiles/tiles_default_view.cc

 // Copyright 2016 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/tiles/tiles_default_view.h"
 
 #include "ash/metrics/user_metrics_action.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/session/session_controller.h"
 #include "ash/shell.h"
@@ skipping 68 matching lines @@
       base::i18n::GetConfiguredLocale() == kHebrewLocale) {
     // The asset for the help button is a question mark '?'. Normally this asset
     // is flipped in RTL locales, however Hebrew uses the LTR '?'. So the
     // flipping must be disabled. (crbug.com/475237)
     help_button_->EnableCanvasFlippingForRTLUI(false);
   }
   help_button_->SetEnabled(can_show_web_ui);
   AddChildView(help_button_);
   AddChildView(TrayPopupUtils::CreateVerticalSeparator());
 
-  night_light_button_ = new NightLightToggleButton(this);
-  night_light_button_->SetEnabled(can_show_web_ui);
-  AddChildView(night_light_button_);
-  AddChildView(TrayPopupUtils::CreateVerticalSeparator());
+  if (NightLightController::IsFeatureEnabled()) {
+    night_light_button_ = new NightLightToggleButton(this);
+    night_light_button_->SetEnabled(can_show_web_ui);
+    AddChildView(night_light_button_);
+    AddChildView(TrayPopupUtils::CreateVerticalSeparator());
+  }
 
   lock_button_ =
       new SystemMenuButton(this, TrayPopupInkDropStyle::HOST_CENTERED,
                            kSystemMenuLockIcon, IDS_ASH_STATUS_TRAY_LOCK);
   lock_button_->SetEnabled(can_show_web_ui &&
                            Shell::Get()->session_controller()->CanLockScreen());
 
   AddChildView(lock_button_);
   AddChildView(TrayPopupUtils::CreateVerticalSeparator());
 
@@ skipping 10 matching lines @@
 
 void TilesDefaultView::ButtonPressed(views::Button* sender,
                                      const ui::Event& event) {
   DCHECK(sender);
   if (sender == settings_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_SETTINGS);
     Shell::Get()->system_tray_controller()->ShowSettings();
   } else if (sender == help_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_HELP);
     Shell::Get()->system_tray_controller()->ShowHelp();
-  } else if (sender == night_light_button_) {
+  } else if (NightLightController::IsFeatureEnabled() &&
+             sender == night_light_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_NIGHT_LIGHT);
     Shell::Get()->night_light_controller()->Toggle();
     night_light_button_->Update();
   } else if (sender == lock_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_LOCK_SCREEN);
     chromeos::DBusThreadManager::Get()
         ->GetSessionManagerClient()
         ->RequestLockScreen();
   } else if (sender == power_button_) {
     ShellPort::Get()->RecordUserMetricsAction(UMA_TRAY_SHUT_DOWN);
     Shell::Get()->lock_state_controller()->RequestShutdown();
   }
 }
 
 views::View* TilesDefaultView::GetHelpButtonView() const {
   return help_button_;
 }
 
 const views::CustomButton* TilesDefaultView::GetShutdownButtonViewForTest()
     const {
   return power_button_;
 }
 
 }  // namespace ash