Add EventTargeterDelegate for EventTargeter in mus-ws.

services/ui/ws/event_dispatcher.h

Index: services/ui/ws/event_dispatcher.h
diff --git a/services/ui/ws/event_dispatcher.h b/services/ui/ws/event_dispatcher.h
index 193786bd6ee5d119c42684623986a3ce9c612e94..1da07968bb4ba5868c01f88531e4509debdce0fd 100644
--- a/services/ui/ws/event_dispatcher.h
+++ b/services/ui/ws/event_dispatcher.h
@@ -17,6 +17,7 @@
 #include "services/ui/public/interfaces/window_manager.mojom.h"
 #include "services/ui/ws/drag_cursor_updater.h"
 #include "services/ui/ws/event_targeter.h"
+#include "services/ui/ws/event_targeter_delegate.h"
 #include "services/ui/ws/modal_window_controller.h"
 #include "services/ui/ws/server_window_observer.h"
 #include "ui/gfx/geometry/rect_f.h"
@@ -41,7 +42,9 @@ class EventDispatcherTestApi;
 }
 
 // Handles dispatching events to the right location as well as updating focus.
-class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
+class EventDispatcher : public ServerWindowObserver,
+                        public DragCursorUpdater,
+                        public EventTargeterDelegate {
  public:
   enum class AcceleratorMatchPhase {
     // Both pre and post should be considered.
@@ -148,6 +151,10 @@ class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
                     const int64_t display_id,
                     AcceleratorMatchPhase match_phase);
 
+  // EventTargeterDelegate:
+  ServerWindow* GetRootWindowContaining(gfx::Point* location_in_display,
+                                        int64_t* display_id) override;
+
  private:
   friend class test::EventDispatcherTestApi;