test(function() {
  assert_equals(typeof navigator.cpuPerformance, 'number',
                'navigator.cpuPerformance returns a number');
  assert_true(Number.isInteger(navigator.cpuPerformance),
              'navigator.cpuPerformance returns an integer value');
  assert_true(navigator.cpuPerformance >= 0,
              'navigator.cpuPerformance returns a non-negative value');
}, 'navigator.cpuPerformance is valid');