chromium/third_party/blink/web_tests/fast/forms/range/range-reset.html

<html
<head>
<script src="../../../resources/js-test.js"></script>
<body>
<p id="description"></p>
<form>
<input id="slider" type="range" min="0" max="100" value="30">
<input id="defaults" type="range">
<input id="step" type="range" step="20">
</form>
<div id="console"></div>
<script>
description("<a href='http://bugs.webkit.org/show_bug.cgi?id=15251'>Bug 15251: REGRESSION: &lt;input type=range&gt; doesn't respond to form.reset() or setting input.value</a>");

function quoteNumber(n)
{
    return "\"" + n + "\"";
}

var slider; // Global needed for eval in shouldBe calls.
function testSliderReset(id)
{
    slider = document.getElementById(id);
    var originalValue = quoteNumber(slider.value);
    debug("Current value is: " + originalValue);

    slider.value = 80;
    shouldBe("slider.value", quoteNumber(80));

    debug("Resetting form");
    document.forms[0].reset();
    shouldBe("slider.value", originalValue);

    debug("");
}

debug("Slider with explicit limits");
testSliderReset("slider");

debug("Slider with default limits, and no explicit value");
testSliderReset("defaults");

debug("Slider with default limits, and a step value");
testSliderReset("step");
</script>
</body>
</html>