Test that changing src attribute triggers load when network state is empty.
Test that it does not trigger load when network state is non-empty.
EVENT(emptied)
TEST(video.networkState == HTMLMediaElement.EMPTY) OK
EVENT(loadstart) TEST(relativeURL(video.currentSrc) == 'content/test.mp4') OK
EVENT(load)
TEST(video.networkState != HTMLMediaElement.EMPTY) OK
END OF TEST

