diff --git a/ui/ozone/platform/x11/x11_window.cc b/ui/ozone/platform/x11/x11_window.cc
index eddc5aee9e633..faa43761a6894 100644
--- a/ui/ozone/platform/x11/x11_window.cc
+++ b/ui/ozone/platform/x11/x11_window.cc
@@ -540,10 +540,19 @@ void X11Window::SetBoundsInPixels(const gfx::Rect& bounds) {
   gfx::Rect new_bounds_in_pixels(bounds.origin(),
                                  AdjustSizeForDisplay(bounds.size()));
 
+  // GetBoundsInPixels() may synchronously dispatch X11 replies via
+  // GeometryCache::GetBoundsPx() → DispatchNow(), which can re-enter the
+  // delegate and delete |this| (see crbug.com/1068755). Guard with a weak
+  // pointer and bail out if that happens.
+  auto weak_this = weak_ptr_factory_.GetWeakPtr();
+  const gfx::Rect current_bounds = GetBoundsInPixels();
+  if (!weak_this) {
+    return;
+  }
   const bool size_changed =
-      GetBoundsInPixels().size() != new_bounds_in_pixels.size();
+      current_bounds.size() != new_bounds_in_pixels.size();
   const bool origin_changed =
-      GetBoundsInPixels().origin() != new_bounds_in_pixels.origin();
+      current_bounds.origin() != new_bounds_in_pixels.origin();
 
   // Assume that the resize will go through as requested, which should be the
   // case if we're running without a window manager.  If there's a window