1-global-variable.html

<!DOCTYPE html>
<html>
<head>
<script>
'use strict';

function LeakObject () {
  this.value = new Array(1024 * 1024).join('X');
}

function addLeak () {
  window.leakObject = new LeakObject();
}

function releaseLeak () {
  window.leakObject = null;
}
</script>
</head>
<body>
<button onclick="addLeak()">Add Leak</button>
<button onclick="releaseLeak()">Release Leak</button>
</body>
</html>