Linux Aura: Fixes and improvements for cursor loader

ui/views/widget/desktop_aura/desktop_cursor_loader_updater.h

-// Copyright (c) 2013 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 UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_CURSOR_LOADER_UPDATER_H_
-#define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_CURSOR_LOADER_UPDATER_H_
-
-#include <memory>
-
-#include "ui/views/views_export.h"
-
-namespace display {
-class Display;
-}
-
-namespace ui {
-class CursorLoader;
-}
-
-namespace views {
-
-// An interface to optionally update the state of a cursor loader. Only used on
-// desktop AuraX11.
-class VIEWS_EXPORT DesktopCursorLoaderUpdater {
- public:
-  virtual ~DesktopCursorLoaderUpdater() {}
-
-  // Creates a new DesktopCursorLoaderUpdater, or NULL if the platform doesn't
-  // support one.
-  static std::unique_ptr<DesktopCursorLoaderUpdater> Create();
-
-  // Called when a CursorLoader is created.
-  virtual void OnCreate(float device_scale_factor,
-                        ui::CursorLoader* loader) = 0;
-
-  // Called when the display has changed (as we may need to reload the cursor
-  // assets in response to a device scale factor or rotation change).
-  virtual void OnDisplayUpdated(const display::Display& display,
-                                ui::CursorLoader* loader) = 0;
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DISPLAY_CHANGE_HANDLER_H_