chromium/third_party/blink/web_tests/editing/deleting/password-delete-contents.html

<!DOCTYPE>
<html>
<head>
<script src="../../resources/js-test.js"></script>
</head>
<body>
<p id="description">This makes sure we are able to delete the contents of a password field: deleting a selection and evaluating the field contents.</p>
<div id="console"></div>
<input type="password" id="passwordField">
<script>

if (!window.testRunner || !window.internals)
    testFailed('This test requires access to window.internals');

var textField;
var desiredString = "hello";
function runTest(element) {
    textField = element;

    textField.value = "helllo";
    textField.focus();

    shouldBe("passwordField.value='helllo'; passwordField.setSelectionRange(3, 4); testRunner.execCommand('Delete', false, null); passwordField.value", "'hello'");

    textField.parentNode.removeChild(textField);
}

runTest(document.getElementById('passwordField'));

</script>
</body>
</html>