[Ozone/x11] events can be dispatched to the wrong window

ui/events/platform/x11/x11_event_source_libevent.h

Index: ui/events/platform/x11/x11_event_source_libevent.h
diff --git a/ui/events/platform/x11/x11_event_source_libevent.h b/ui/events/platform/x11/x11_event_source_libevent.h
index bc2ab738de283445614f2fc7f51015276ff35606..3ef9b92d226f1e5b9b315e01702719f04a932495 100644
--- a/ui/events/platform/x11/x11_event_source_libevent.h
+++ b/ui/events/platform/x11/x11_event_source_libevent.h
@@ -13,6 +13,13 @@
 
 namespace ui {
 
+class Event;
+
+struct EVENTS_EXPORT EventWithPlatformEvent {
+  Event* event;
+  PlatformEvent platform_event;
+};
+
 // Interface for classes that want to receive XEvent directly. Only used with
 // Ozone X11 currently and only events that can't be translated into ui::Events
 // are sent via this path.