manual-test.html

<html>
<head>
<script src="keyboard-polyfill.js"></script>
<style media="screen" type="text/css">
#result {
	margin: 5px;
	display: flex;
	flex-flow: row wrap;
}
#result p {
	border: 1px solid #8080ff;
	background-color: #c0c0ff;
	margin: 4px;
	padding: 2px 4px;
	flex: 1 0 200px;
}
</style>
</head>
<body>

<script>
function get_keyboard_map() {
	var map = navigator.keyboard.getKeyMap();

	var result = document.getElementById("result");
	var keys = Object.keys(map).sort();
	for (i = 0; i < keys.length; i++) {
		var e = document.createElement("p");
		e.textContent = keys[i] + ": " + map[keys[i]];
		result.insertBefore(e, null);
	}
}
</script>

<p>Polyfill test for getKeyMap</p>
<button onclick="get_keyboard_map()">Get Keyboard Map</button>
<div id="result"></div>

</body>
</html>