on", "cubic-bezier(0, -2, 1, 3)");
test_computed_value("transition-timing-function", "cubic-bezier(0, 0.7, 1, 1.3)");

test_computed_value("transition-timing-function", "step-start", "steps(1, start)");
test_computed_value("transition-timing-function", "step-end", "steps(1)");
test_computed_value("transition-timing-function", "steps(4)");
test_computed_value("transition-timing-function", "steps(4, start)");
test_computed_value("transition-timing-function", "steps(2, end)", "steps(2)");
test_computed_value("