
PASS Upgrading a custom element must invoke attributeChangedCallback and connectedCallback before start upgrading another element
PASS Upgrading a custom element must not invoke attributeChangedCallback for the attribute that is changed during upgrading
PASS Mutating a undefined custom element while upgrading a custom element must not enqueue or invoke reactions on the mutated element
PASS Mutating another custom element inside adopted callback must invoke all pending callbacks on the mutated element