Tests XMLHttpRequest 'document' loading with the .responseType and .response attributes.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS responseType property exists.
PASS response property exists.
PASS xhr.responseType has been correctly set to 'document'.
PASS DONE LOADING
PASS received response object of type : object.
PASS exception correctly thrown when xhr.responseType is set to valid value too late in the loading process : InvalidStateError: The object is in an invalid state..
PASS xhr.response is a Document.
PASS xhr.response == xhr.responseXML.
PASS successfullyParsed is true

TEST COMPLETE