ndingClientRect();
          assert.isTrue(rect.height <= window.innerHeight - 100, 'height is less than or equal to viewport height');
        });

        test('sized, scrolling element with margin is centered in viewport', function() {
          var el = fixture('sized-x');
          el.classList.add('with-margin');
          makeScrolling(el);
          el.refit();
          var rect = el.getBoundingClientRect();
          assert.closeTo(rect.left - (window.innerWidth - rect.right), 0, 5, 'centered hori