Test that XMLHttpRequest raises exceptions when it should.

new XMLHttpRequest()
PASS: req.setRequestHeader("Foo", "bar") threw exception InvalidStateError: The object is in an invalid state..
PASS: req.send(null) threw exception InvalidStateError: The object is in an invalid state..
open()
PASS: req.setRequestHeader() threw exception TypeError: Not enough arguments.
PASS: req.setRequestHeader("Foo") threw exception TypeError: Not enough arguments.
send()
PASS: req.send(null) threw exception InvalidStateError: The object is in an invalid state..
PASS: req.overrideMimeType("text/plain") threw exception InvalidStateError: The object is in an invalid state..
PASS: req.setRequestHeader("Foo", "bar") threw exception InvalidStateError: The object is in an invalid state..
PASS: req.getResponseHeader() threw exception TypeError: Not enough arguments.
PASS: req.open() threw exception TypeError: Not enough arguments.
PASS: req.open(null) threw exception TypeError: Not enough arguments.