Testing that DOM.childNodeRemoved is correctly triggered when all the parent children of a node are removed at once.

Parent container is now empty
Target element should have been moved after this line:
Target element

Removing node div#target_element
Inserting node div#target_element into p#final_container
Removing node div#before
Removing node div#after
Inserting node <text node "Parent container is now empty"> into div#parent_container