Over if bug 560932 we discussed increasing the “hung plugin” timeout, but
ultimately decided to leave it set at 10 seconds, as the value of OOPP is
decreased if it takes painfully long to kill a hung plugin.

However, now that 3.6.4 has shipped, we are seeing an increasing number of
reports that some users are unable to play Farmville, because Farmville hangs
the browser long enough for out timeout to trigger and kill it.