Test that Audio() sets 'preload' attribute.

RUN(mediaElement = new Audio())

++ Test initial attribute value
EXPECTED (mediaElement.getAttribute('preload') == 'auto') OK
EXPECTED (mediaElement.preload == 'auto') OK

RUN(mediaElement.src = 'content/test.wav')
RUN(mediaElement.load())

++ Test after 'canplaythrough' event
EXPECTED (mediaElement.getAttribute('preload') == 'auto') OK
EXPECTED (mediaElement.preload == 'auto') OK
END OF TEST