keyboard scroll does not work if child element of scrollable element focused

[dsolskyi]

For example scrollable element
<div class="list">
<ul>
<li tabindex="-888">
<a>Some text
</li>
</ul>
</div>

In this case it`s does not scrolling, with keyboard, becouse сondition are not met:
this.elementKeydown = function (event) {
if (document.activeElement === _this.$element[0])