diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 3c0b9aeb9f326..a8a0514680e06 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -1042,8 +1042,18 @@ void RenderWidgetHostViewAura::ShowWithVisibility(
   }
 
   window_->Show();
+#if BUILDFLAG(IS_WIN)
+  // ShowImpl -> ... -> UpdateLegacyWin can spin a nested Win32 message loop and
+  // synchronously delete `this` (see the WARNING in
+  // NotifyHostAndDelegateOnWasShown). Guard the post-ShowImpl access below.
+  base::WeakPtr<RenderWidgetHostViewAura> weak_this =
+      weak_ptr_factory_.GetWeakPtr();
+#endif  // BUILDFLAG(IS_WIN)
   ShowImpl(page_visibility);
 #if BUILDFLAG(IS_WIN)
+  if (!weak_this) {
+    return;
+  }
   if (page_visibility != PageVisibilityState::kVisible &&
       legacy_render_widget_host_HWND_) {
     legacy_render_widget_host_HWND_->Hide();