Test of requestIdleCallback timeout behavior


FAIL requestIdleCallback not scheduled when event loop is busy. assert_false: IdleDeadline.didTimeout MUST be false if requestIdleCallback wasn't scheduled due to a timeout expected false got true
FAIL requestIdleCallback scheduled with timeout when event loop is busy. assert_true: IdleDeadline.timeRemaining MUST be equal to zero if requestIdleCallback was scheduled due to a timeout expected true got false