deltaScrollTop, duration));
            requestAnimationFrame(updateFrame);
          } else {
            scrollTo(scrollLeft, scrollTop);
          }
        }).bind(this);

        updateFrame();
      }

    } else if (options.behavior === 'silent') {
      var headers = Polymer.AppLayout.queryAllRoot('app-header', document.body);

      headers.forEach(function(header) {
        header.setAttribute('silent-scroll', '');
      });

      // Browsers keep the scroll momentum even if the bottom of the scr