, 'region scrollLeft');
          assert.equal(region.scrollTop, y, 'region scrollTop');
          done();
        }, 100);

      });

      test('behavior: silent', function() {
        Polymer.AppLayout.scroll({left: 100, top: 200, behavior: 'silent'});

        assert.isTrue(document.documentElement.classList.contains('app-layout-silent-scroll'));
      });

      test('behavior: smooth', function(done) {
        var scrollSpy = sinon.spy();
        window.addEventListener('scroll', scrollSpy);
        