4 When 'ended' event fires, change the source.
5 Verify that 'ended' event fires again on different source.
7 EXPECTED (audio.playbackRate > '0') OK
8 EXPECTED (audio.ended == 'true') OK
9 RUN(audio.playbackRate = 0)
10 EXPECTED (audio.ended == 'true') OK
11 RUN(audio.playbackRate = -0.1)
12 EXPECTED (audio.ended == 'false') OK
13 EXPECTED (audio.ended == 'false') OK
16 EXPECTED (audio.ended == 'true') OK