Forms: Don't run focusin action when gaining focus because of window management

Adobe Reader doesn't do it, and with reason, because otherwise we end up
with:
 * Run focus in script
 * script shows alert()
 * form loses focus and gains it again once the alert() is closed
 * infinite loop

The same fix we did in e457ceb7 but for
the rest of the widgets

BUGS: 472756
(cherry picked from commit f940ca1e)