Hide Night Light behind a flag

ash/shell.h

 // 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.
 
 #ifndef ASH_SHELL_H_
 #define ASH_SHELL_H_
 
 #include <memory>
 #include <utility>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/public/cpp/shelf_types.h"
 #include "ash/session/session_observer.h"
+#include "ash/system/night_light/night_light_controller.h"
 #include "ash/wm/system_modal_container_event_filter_delegate.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "ui/aura/window.h"
 #include "ui/display/screen.h"
 #include "ui/events/event_target.h"
 #include "ui/wm/core/cursor_manager.h"
 #include "ui/wm/public/activation_change_observer.h"
@@ skipping 91 matching lines @@
 class LocaleNotificationController;
 class LockStateController;
 class LogoutConfirmationController;
 class LockScreenController;
 class MagnificationController;
 class MaximizeModeController;
 class MediaController;
 class MouseCursorEventFilter;
 class MruWindowTracker;
 class NewWindowController;
-class NightLightController;
 class OverlayEventFilter;
 class PaletteDelegate;
 class PartialMagnificationController;
 class PowerButtonController;
 class PowerEventObserver;
 class ProjectingObserver;
 class ResizeShadowController;
 class ResolutionNotificationController;
 class RootWindowController;
 class ShellPort;
@@ skipping 193 matching lines @@
   }
   MaximizeModeController* maximize_mode_controller() {
     return maximize_mode_controller_.get();
   }
   MediaController* media_controller() { return media_controller_.get(); }
   MruWindowTracker* mru_window_tracker() { return mru_window_tracker_.get(); }
   NewWindowController* new_window_controller() {
     return new_window_controller_.get();
   }
   NightLightController* night_light_controller() {
+    DCHECK(NightLightController::IsFeatureEnabled());

[James Cook, 2017/06/02 23:40:05]

If you want to do this I would move the implementation into the .cc file and not
include the header. (It's OK to have hacker_style() methods with the impl in the
.cc as long as the impl is cheap.)

[afakhry, 2017/06/03 00:09:02]

Done.

     return night_light_controller_.get();
   }
   SessionController* session_controller() { return session_controller_.get(); }
   ShelfController* shelf_controller() { return shelf_controller_.get(); }
   ShelfModel* shelf_model();
   ShutdownController* shutdown_controller() {
     return shutdown_controller_.get();
   }
   SystemTrayController* system_tray_controller() {
     return system_tray_controller_.get();
@@ skipping 475 matching lines @@
   base::ObserverList<ShellObserver> shell_observers_;
 
   scoped_refptr<base::SequencedWorkerPool> blocking_pool_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_