Tests that uncaught exceptions are logged into console.Bug 47250.

uncaught-in-iframe.html:18 Uncaught Error: Exception in inline script.
    at a (uncaught-in-iframe.html:18:11)
    at b (uncaught-in-iframe.html:23:5)
    at uncaught-in-iframe.html:26:1
a @ uncaught-in-iframe.html:18
b @ uncaught-in-iframe.html:23
(anonymous) @ uncaught-in-iframe.html:26
uncaught-in-iframe.html:11 Uncaught Error: Exception in 'load' event listener.
    at f (uncaught-in-iframe.html:11:15)
    at uncaught-in-iframe.html:13:5
f @ uncaught-in-iframe.html:11
(anonymous) @ uncaught-in-iframe.html:13
uncaught-in-iframe.html:6 Uncaught Error: Exception in setTimeout callback.
    at bar (uncaught-in-iframe.html:6:23)
    at uncaught-in-iframe.html:8:13
bar @ uncaught-in-iframe.html:6
(anonymous) @ uncaught-in-iframe.html:8
setTimeout
f @ uncaught-in-iframe.html:4
(anonymous) @ uncaught-in-iframe.html:13