Tests compositor animated css handling.
Expired count: 1, elaspedTime: 500
Expired count: 2, elaspedTime: 1000
Event [animationstart] at 0 sec
Screenshot rgba: 255,0,0,255
Expired count: 3, elaspedTime: 1500
Event [animationiteration] at 1 sec
Screenshot rgba: 1,0,254,255
Expired count: 4, elaspedTime: 2000
Expired count: 5, elaspedTime: 2500
Event [animationiteration] at 2 sec
Expired count: 6, elaspedTime: 3000
Expired count: 7, elaspedTime: 3500
Event [animationiteration] at 3 sec
Screenshot rgba: 1,0,254,255
Expired count: 8, elaspedTime: 4000
Screenshot rgba: 255,0,0,255
Expired count: 9, elaspedTime: 4500
Event [animationend] at 4 sec
Screenshot rgba: 0,0,255,255
Expired count: 10, elaspedTime: 5000
Screenshot rgba: 0,0,255,255