Comment 5 for bug 570380

Firefox could be outright dying, or it could be blocking on a dialog
window. There is no way to know without running the test suite using
a live console. Since this problem is intermittent, I suspect it is
simply the browser dying, and not blocking. If it were blocking on a
dialog, it would die every time, not at random.

I do not know the frequency with the browser hangs, so I assume it
would be annoying to try and catch the hang by watching a live window.

Even if we do discover what is hanging, I am not sure we will be able
to do anything besides restarting the suite anyway.

I am hesitant to hack windmill itself to fix this. Adding both
browser death detection and the ability to restart the browser
mid-test is more work than we can do. However, we may be able to add
just the browser death detection to windmill, cause windmill to die
really loudly, then use that death to signal a retry for our own
suite. Worth thinking about.