chromium/content/test/data/page_with_blur.html

<!DOCTYPE html>
<html>
<head>
<script>

window.onload = function() {
  document.body.onblur = function() {
    domAutomationController.send("document-blur");
  }
}

</script>
</head>

<body>
This page has a blur event.
</body>
</html>