Use ui::Event instead of mojom::EventPtr in mash/wm.

mash/wm/root_window_controller.cc

Index: mash/wm/root_window_controller.cc
diff --git a/mash/wm/root_window_controller.cc b/mash/wm/root_window_controller.cc
index 34ac1a9ec77ab31befb752199ffc61ce3702cd84..ca74674d48c46684746311f0d51673472cbf9d07 100644
--- a/mash/wm/root_window_controller.cc
+++ b/mash/wm/root_window_controller.cc
@@ -82,14 +82,13 @@ mus::WindowManagerClient* RootWindowController::window_manager_client() {
   return window_manager_->window_manager_client();
 }
 
-void RootWindowController::OnAccelerator(uint32_t id,
-                                         mus::mojom::EventPtr event) {
+void RootWindowController::OnAccelerator(uint32_t id, const ui::Event& event) {
   switch (id) {
     case kWindowSwitchAccelerator:
       window_manager_client()->ActivateNextWindow();
       break;
     default:
-      app_->OnAccelerator(id, std::move(event));
+      app_->OnAccelerator(id, event);
       break;
   }
 }