Add `dropmarkerhidden` to `observedAttributes` so callback runs again and the button type tracks the secondary-action count on every show Differential Revision: https://phabricator.services.mozilla.com/D309429
Add `dropmarkerhidden` to `observedAttributes` so callback runs again and the button type tracks the secondary-action count on every show Differential Revision: https://phabricator.services.mozilla.com/D309429