assertComputed(styled.$.mixin3, '1px', 'margin-top');
    assertComputed(styled.$.mixin4, '2px');
    assertComputed(styled.$.mixin4, '2px', 'padding-top');
    assertComputed(styled.$.mixin4, '2px', 'margin-top');
  });

  test('mixins apply with url values', function() {
    var url = 'http://www.google.com/icon.png';
    var e = styled.$.child;
    var actual, unescaped, propertyName;
    if (window.ShadyCSS && ShadyCSS.nativeCssApply) {
      actual = getComputedStyle(e).getPropertyValue('--mixin2');
  