title: Chrome Extension that replace a text in gmail chat
body: <p>I used Chrome Content Scripts to inject this script :</p>
  
  <pre><code>$('textarea').keyup(function(evt){
     var txt = $(this).val();
     $(this).val(txt.replace(/:\u06CC\s|:\u064A\s/g, ":D "));  
  });     
  </code></pre>
  
  <p>This must apply to chat textarea that appears after user wants to chat,
  but chrome injects the script  between "document_end" and immediately after the window.onload event fires. </p>
  
  <p>So it doesn't work.</p>