Test that 'webkitplaybacktargetavailabilitychanged' event is sent when at least one video element has playable media.
EVENT( webkitplaybacktargetavailabilitychanged )
EXPECTED (event.availability == 'not-available') OK
** simulate device becoming available
** set src on video that does not have event listener
EXPECTED (event.availability == 'available') OK
END OF TEST