title: How can i capture the download progress in chrome extension
body: <p>I am creating a chrome extension which moniters the download progress. I am able the capture the download begin and download complete events but have no idea on how to get the changed progress? Please help.
  Below is my download listener</p>
  
  <pre><code>function AddDownloadListener() {
      //--------------------------------------------------------------------------------------------------------------
  
      chrome.downloads.onCreated.addListener(DownloadCreated);
      chrome.downloads.onChanged.addListener(DownloadChanged);
  
  
  
      function DownloadCreated(el) {
          console.log("Download Begins");
          console.log(el);
          mobjPortToFoxtrot.postMessage({ message: "Download Begins", element: el });
      }
      //--------------------------------------------------------------------------------------------------------------
          function DownloadChanged(el) {
          if (el.danger === undefined || el.danger == null) {
              console.log(el.state.current);
              mobjPortToFoxtrot.postMessage({ message: el.state.current, element: el });
          }
          else {
              console.log("dangerous content");
              mobjPortToFoxtrot.postMessage({ message: "dangerous content", element: el });
          }
          console.log(el);
      }
  }
  </code></pre>