title: window:scroll event doesn't trigger with @HostListener
body: <p>I have this <code>@HostListener</code> in my component that is supposed to listened on the scroll event on the window object :</p>
  <pre><code> export class MapComponent implements OnInit {
    @HostListener('window:scroll', ['$event'])
    onScroll(e) {
      console.log(e.target);
    } }
  </code></pre>
  <p>Nothing happens. If I change it to a click event, it detects the event on the whole window, as expected :</p>
  <pre><code>    export class MapComponent implements OnInit {
    @HostListener('window:click', ['$event'])
    onScroll(e) {
      console.log(e.target);
    } }
  </code></pre>
  <p>I tried to set a scroll event directly on the main div, or with an eventListener on the window, nothing works.</p>
  <p>Any idea why ?</p>