title: "Violation: Added non-passive event listener" when no JavaScript present
body: <blockquote>
    <p>[Violation] Added non-passive event listener to a scroll-blocking 'mousewheel'event. Consider marking event handler as 'passive' to make the page more responsive. See <a href="https://www.chromestatus.com/feature/5745543795965952" rel="nofollow noreferrer">https://www.chromestatus.com/feature/5745543795965952</a></p>
  </blockquote>
  
  <p>I'm trying to understand this warning.</p>
  
  <p>I've created the simplest of html files:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
      &lt;meta charset="UTF-8"&gt;
      &lt;title&gt;Document&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;select name="" id=""&gt;&lt;/select&gt;
  &lt;/body&gt;
  &lt;/html&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Running this in Chrome (Version 61.0.3163.100 (Official Build) (64-bit)), and clicking on the select element shows the above error in the console:</p>
  
  <p><a href="https://i.stack.imgur.com/uzndl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uzndl.png" alt="Violation Message"></a></p>
  
  <p>I've done some brief reading of other posts and there's a lot of times this is due to frameworks or after the js code ran preventDefault() on the event.</p>
  
  <p>However, in the above example there is no javascript running, so surely there should be no error? The <a href="https://github.com/WICG/EventListenerOptions/blob/gh-pages/explainer.md" rel="nofollow noreferrer">md doc referenced in the violation</a> text states:</p>
  
  <blockquote>
    <p>Developers can annotate touch and wheel listeners with {passive: true} to indicate that they will never invoke preventDefault</p>
  </blockquote>
  
  <p>There are no <code>touch and wheel listeners</code> in the file above.</p>