Test onended with Different Playback Rates

Run the following tests in order. In all cases the onended event should be fired. See crbug.com/484935.

1. The onended event should occur after about sec.

2. The onended event should occur after about sec.

3. The onended event should occur after about sec.

4. The onended event should occur after approximately sec, but may take longer.

Rate 1Rate 2Rate 1/2Rate variable