Chrome Progress Rich Notification Status won't Move Up

I tried making a Chrome progress Rich Notification but the status bar won't move.

I would think this code would work. The status bar will go up by 1% every 40ms. The notification disappears after 4 seconds (happens to be 100% too). I think there is something wrong with my setInterval

var notifyStatus = function(title, message) {
  var k = 0;
  chrome.notifications.create('', {
    'type':    'progress',
    'iconUrl': 'images/icon128.png',
    'title':   title,
    'message': message || '',
    'progress': setInterval(function() {
        if (k>100) {k;}
        else {k++;}
    },40)
  }, function(nid) {
    // Automatically close the notification in 4 seconds.
    window.setTimeout(function() {
      chrome.notifications.clear(nid);
    }, 4000);
  });
};  

Currently you're assigning progress to whatever value setInterval returns just once.

You need to update the notification each 40ms with the new progress value using chrome.notifications.update:

var notifyStatus = function(title, message, timeout) {
  chrome.notifications.create({
    type: 'progress',
    iconUrl: 'images/icon128.png',
    title: title,
    message: message || '',
    progress: 0
  }, function(id) {
    // Automatically close the notification in 4 seconds by default
    var progress = 0;
    var interval = setInterval(function() {
      if (++progress <= 100) {
        chrome.notifications.update(id, {progress: progress}, function(updated) {
          if (!updated) {
            // the notification was closed
            clearInterval(interval);
          }
        });
      } else {
        chrome.notifications.clear(id);
        clearInterval(interval);
      }
    }, (timeout || 4000) / 100);
  });
};