This test moves the iframe between two documents - once using this sequence:

    document1.body.removeChild(iframe);
    document2.body.appendChild(iframe);

and then using 'adoptNode':

    document2.adoptNode(iframe);
    document2.body.appendChild(iframe);

In the second case, the content of iframe should not be re-loaded and 'load' event should not be fired. Also, the timer started before reparenting should survive transition and fire.

Test also verifies that document.adoptNode() in case of not-rendered document (loaded by XMLHttpRequest) does not preserve the content of iframe.

Test succeeds if there are 'PASS' messages below and no 'FAIL' messages.