1 Test that changing src attribute triggers load when network state is empty.
2 Test that it does not trigger load when network state is non-empty.
4 TEST(video.networkState == HTMLMediaElement.EMPTY) OK
5 EVENT(begin) TEST(relativeURL(video.currentSrc) == 'content/test.mp4') OK
7 TEST(video.networkState != HTMLMediaElement.EMPTY) OK