title: Error "Found 3 elements with non-unique id #input"
body: <p>I'm using Polymer with Chrome 63.0.3239.108 (updated this morning) and I got some new errors while launching my webapp:</p>
  
  <pre class="lang-none prettyprint-override"><code>[DOM] Found 3 elements with non-unique id #input
  </code></pre>
  
  <p>Here's my code :</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div class="card-content" on-keypress="_keyHandler"&gt;
     &lt;paper-input id="login" label="[[i18n('uid')]]"&gt;&lt;/paper-input&gt;
     &lt;paper-input id="pwd" label="[[i18n('pwd')]]" type="password"&gt;&lt;/paper-input&gt;
     &lt;paper-input id="server" label="[[i18n('server')]]"&gt;&lt;/paper-input&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Yeah, <code>&lt;paper-input&gt;</code> elements have the same id, but what can I do to remove this console error?</p>
  
  <p>Thanks a lot</p>