chromium/third_party/blink/web_tests/fast/forms/button/button-value.html

<html>
<head>
<script>
function test() {
	if (window.testRunner) {
		testRunner.dumpAsText();
	}
	var but = document.getElementById('button');
	but.value = 'Success';
	document.writeln("Button value is: " + but.value);
}
</script>
</head>
<body>
<p>Tests: HTMLButtonElement::value</p>

<p>
This test changes the value of the button. The original value is "Fail"; the new value should be "Success"
</p>

<hr>

<input type=button id='button' value='Fail'></input>

</body>
<script>test()</script>
</html>