Test for http://bugs.webkit.org/show_bug.cgi?id=23721 Changing dropdown's selectedIndex within onchange handler fires another onchange.

To test interactively: focus on the first select (don't change it).
Change the second select to "two"
Focus on the third, then click here.

This select changes on focus: should not fire onchange.

This select changes on change: should only fire onchange once.

This select is changed by a timeout in the test script. It should not fire onchange.