title: chrome.windows.getAll() is undefined?
body: <p>I want to write an extension (a session manager which has more features and eye candy than the ones already in the gallery) for google chrome / chromium.</p>
  
  <p>But I can't get the following code to work:</p>
  
  <pre><code>function list_session() {
   var list = [];
   chrome.windows.getAll(
    {"populate" : true},
  
    function (window_list) {
     for(window in window_list) {
      list.concat(window.tabs);
     }
    }
   );
   console.log(list);
   return list;
  }
  </code></pre>
  
  <p>It's a fairly simple example for the use of the google api, but instead of a list of tabs I get only 'undefined'values in return. Furthermore, the window list seems to be empty.</p>
  
  <p>I'm currently running Chromium 7.0.517.44 (64615) under Ubuntu 10.10. I've tried the official chrome release from google as well with the same results.</p>
  
  <p>API documentation can be found here:
  <a href="http://code.google.com/chrome/extensions/windows.html" rel="noreferrer">http://code.google.com/chrome/extensions/windows.html</a></p>
  
  <p>phineas</p>