diff --git a/ui/base/x/x11_whole_screen_move_loop.cc b/ui/base/x/x11_whole_screen_move_loop.cc
index 71ec09e003fcf..d63595de0b105 100644
--- a/ui/base/x/x11_whole_screen_move_loop.cc
+++ b/ui/base/x/x11_whole_screen_move_loop.cc
@@ -237,7 +237,13 @@ void X11WholeScreenMoveLoop::EndMoveLoop() {
 
   // Restore the previous dispatcher.
   nested_dispatcher_.reset();
+  // The delegate callout can synchronously destroy |this| (e.g. the source
+  // X11Window is closed while handling the SendXdndLeave short-circuit).
+  base::WeakPtr<X11WholeScreenMoveLoop> alive(weak_factory_.GetWeakPtr());
   delegate_->OnMoveLoopEnded();
+  if (!alive) {
+    return;
+  }
   grab_input_window_events_.Reset();
   connection->DestroyWindow({grab_input_window_});
   grab_input_window_ = x11::Window::None;