mus: Keep track of the drag cursor during DnD operations.

services/ui/ws/event_dispatcher.h

 // Copyright 2015 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_WS_EVENT_DISPATCHER_H_
 #define SERVICES_UI_WS_EVENT_DISPATCHER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <utility>
 
 #include "base/macros.h"
 #include "services/ui/common/types.h"
 #include "services/ui/public/interfaces/event_matcher.mojom.h"
+#include "services/ui/ws/drag_cursor_updater.h"
 #include "services/ui/ws/modal_window_controller.h"
 #include "services/ui/ws/server_window_observer.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 namespace ui {
 class Event;
 class KeyEvent;
 class LocatedEvent;
 
 namespace ws {
 
 class Accelerator;
 class DragController;
 class DragSource;
 class DragTargetConnection;
 class EventDispatcherDelegate;
 class ServerWindow;
 class WindowTree;
 
 namespace test {
 class EventDispatcherTestApi;
 }
 
 // Handles dispatching events to the right location as well as updating focus.
-class EventDispatcher : public ServerWindowObserver {
+class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
  public:
   enum class AcceleratorMatchPhase {
     // Both pre and post should be considered.
     ANY,
 
     // PRE_TARGETs are not considered, only the actual target and any
     // accelerators registered with POST_TARGET.
     POST_ONLY,
   };
 
@@ skipping 172 matching lines @@
   // |window|. |window| may be null.
   void CancelImplicitCaptureExcept(ServerWindow* window);
 
   // ServerWindowObserver:
   void OnWillChangeWindowHierarchy(ServerWindow* window,
                                    ServerWindow* new_parent,
                                    ServerWindow* old_parent) override;
   void OnWindowVisibilityChanged(ServerWindow* window) override;
   void OnWindowDestroyed(ServerWindow* window) override;
 
+  // DragCursorUpdater:
+  void OnDragCursorUpdated() override;
+
   EventDispatcherDelegate* delegate_;
 
   ServerWindow* capture_window_;
   ClientSpecificId capture_window_client_id_;
 
   std::unique_ptr<DragController> drag_controller_;
 
   ModalWindowController modal_window_controller_;
 
   bool mouse_button_down_;
@@ skipping 22 matching lines @@
       AcceleratorMatchPhase::ANY;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(EventDispatcher);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_EVENT_DISPATCHER_H_