title: Can I modify chrome://extensions/ page with JavaScript(user script)?
body: <p>I'd like to use JavaScript to add a search bar for <code>chrome://extensions/</code> page, so I created a file called test.user.js, and write scripts in it:  </p>
  
  <pre><code>// ==UserScript==
  // @name       chromeex
  // @namespace  chromeex
  // @version    v1.0
  /* @reason
   * just a test
   * @end
   */
  // @match     chrome://extensions/
  //
  // ==/UserScript==
  
  (function(){
      alert("haha");
  }());
  </code></pre>
  
  <p>But when I load it in Chrome, it said Invalid header, finally I found out that it's <code>@match chrome://extensions/</code> that cause the error. Is there a walkaround for this?</p>