The Mac wrench menu zoom controls honor the global enabled state of the zoom commands.

app/menus/button_menu_item_model.cc

Index: app/menus/button_menu_item_model.cc
diff --git a/app/menus/button_menu_item_model.cc b/app/menus/button_menu_item_model.cc
index c1c7f7ab5a59802242337d152d786d54909495b2..94949e4f9d023b84ea6ee420ec2b10d54870fce3 100644
--- a/app/menus/button_menu_item_model.cc
+++ b/app/menus/button_menu_item_model.cc
@@ -102,4 +102,10 @@ void ButtonMenuItemModel::ActivatedCommand(int command_id) {
     delegate_->ExecuteCommand(command_id);
 }
 
+bool ButtonMenuItemModel::IsEnabledAt(int index) const {
+  if (delegate_)
+    return delegate_->IsCommandIdEnabled(items_[index].command_id);
+  return true;
+}
+
 }  // namespace menus