Style(element);
    property = property || 'border-top-width';
    assert.equal(computed[property], value, 'computed style incorrect for ' + property);
  }

  var styled = document.querySelector('x-scope');

  test('variable mixins calculated correctly and inherit', function() {
    if (!window.ShadyCSS || ShadyCSS.nativeCss) {
      this.skip();
    }
    var suffix = window.ShadyCSS.ApplyShim._separator + 'border';
    var e = styled;
    let mixin1 = ShadyCSS.ScopingShim.getComputedStyleValue(e, '--mixin