aura-mus: add a drag representation image.

services/ui/demo/mus_demo_internal.h

 // Copyright 2017 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 SERVICES_UI_DEMO_MUS_DEMO_INTERNAL_H_
 #define SERVICES_UI_DEMO_MUS_DEMO_INTERNAL_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 25 matching lines @@
   bool OnWmSetProperty(aura::Window* window,
                        const std::string& name,
                        std::unique_ptr<std::vector<uint8_t>>* new_data) final;
   void OnWmSetModalType(aura::Window* window, ModalType type) final;
   void OnWmSetCanFocus(aura::Window* window, bool can_focus) final;
   aura::Window* OnWmCreateTopLevelWindow(
       ui::mojom::WindowType window_type,
       std::map<std::string, std::vector<uint8_t>>* properties) final;
   void OnWmClientJankinessChanged(const std::set<aura::Window*>& client_windows,
                                   bool janky) final;
+  void OnWmBuildDragImage(const gfx::Point& cursor_location,
+                          const SkBitmap& drag_image,
+                          const gfx::Vector2d& drag_image_offset,
+                          ui::mojom::DragEventSource source) final;
+  void OnWmMoveDragImage(const gfx::Point& cursor_location) final;
+  void OnWmDestroyDragImage() final;
   void OnWmWillCreateDisplay(const display::Display& display) final;
   void OnWmNewDisplay(std::unique_ptr<aura::WindowTreeHostMus> window_tree_host,
                       const display::Display& display) final;
   void OnWmDisplayRemoved(aura::WindowTreeHostMus* window_tree_host) final;
   void OnWmDisplayModified(const display::Display& display) final;
   ui::mojom::EventResult OnAccelerator(
       uint32_t id,
       const ui::Event& event,
       std::unordered_map<std::string, std::vector<uint8_t>>* properties) final;
   void OnWmPerformMoveLoop(aura::Window* window,
                            ui::mojom::MoveLoopSource source,
                            const gfx::Point& cursor_location,
                            const base::Callback<void(bool)>& on_done) final;
   void OnWmCancelMoveLoop(aura::Window* window) final;
   void OnWmSetClientArea(
       aura::Window* window,
       const gfx::Insets& insets,
       const std::vector<gfx::Rect>& additional_client_areas) final;
   bool IsWindowActive(aura::Window* window) final;
   void OnWmDeactivateWindow(aura::Window* window) final;
 
   DISALLOW_COPY_AND_ASSIGN(MusDemoInternal);
 };
 
 }  // namespace demo
 }  // namespace ui
 
 #endif  // SERVICES_UI_DEMO_MUS_DEMO_INTERNAL_H_