<!DOCTYPE html>
<html>
    <head>
        <title>Lifecycle</title>
        <script>
         let frozenness = 0;
         document.addEventListener("freeze", function() {
             frozenness += 1;
         });
         document.addEventListener("resume", function() {
             frozenness -= 1;
         });
        </script>
    </head>
    <body>
    </body>
</html>