MacViews: Be robust against Views manipulating Layers during Widget::Close().

ui/views/cocoa/bridged_native_widget.mm

Index: ui/views/cocoa/bridged_native_widget.mm
diff --git a/ui/views/cocoa/bridged_native_widget.mm b/ui/views/cocoa/bridged_native_widget.mm
index b787dbc9549e986fd395cc5c8355a1408a58f427..da2361c07492b0fee524db6a1fb4ed1f5383a728 100644
--- a/ui/views/cocoa/bridged_native_widget.mm
+++ b/ui/views/cocoa/bridged_native_widget.mm
@@ -1046,6 +1046,11 @@ void BridgedNativeWidget::ClearAssociationForView(const views::View* view) {
 }
 
 void BridgedNativeWidget::ReorderChildViews() {
+  // Ignore layer manipulation during a Close(). This can be reached during the
+  // orderOut: in Close(), which notifies visibility changes to Views.
+  if (!bridged_view_)
+    return;
+
   RankMap rank;
   Widget* widget = native_widget_mac_->GetWidget();
   RankNSViews(widget->GetRootView(), associated_views_, &rank);