title: html autocomplete on input text does not work; no history shown
body: <p>Here is my simple html file, I ran on firefox 47; the autocomplete attribute does not have any effect.</p>
  
  <p>I'm expecting press "down" arrow will show my history. However, it does not work. Why?</p>
  
  <p>Note1: I've checked Firefox | Options | Privacy | Firefox will: Remember History; I've also disabled all add-ins and restarted Firefox; still not work.</p>
  
  <p>Note2: these code are just running on client browser, I don't need a form to submit to server. All I need is to click the button, then retrieve the text from input and do something in JavaScript.</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&gt;
    &lt;head&gt;
      &lt;meta content="text/html;charset=utf-8" http-equiv="Content-Type"&gt;
      &lt;meta content="utf-8" http-equiv="encoding"&gt;
      &lt;script type="text/javascript"&gt;
        function runCommand(command_str) {
  
        };
      &lt;/script&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;input id="command_text" type="text" autocomplete="on" size="80" &gt; 
      &lt;button onclick="runCommand(document.getElementById('command_text').value)"&gt;Run Command&lt;/button&gt; 
    &lt;/body&gt;
  &lt;/html&gt;</code></pre>
  </div>
  </div>
  </p>