chromium/third_party/blink/web_tests/fast/dom/cross-frame-node-prototype.html

<p>Test for <a href="https://bugs.webkit.org/show_bug.cgi?id=26520">bug 26520</a>:
Accessing a DOM node from a parent window in a child iframe moves the prototype to the child iframe and resets it in the parent window.</p>
<script type="text/javascript">
if (window.testRunner)
    testRunner.dumpAsText();

HTMLInputElement.prototype.foo = 'foo';

function test(value)
{
    document.getElementById("result").innerHTML = (value == "foo") ? "PASS" : ("FAIL: " + value);
}

</script>

<iframe src="resources/cross-frame-node-prototype-iframe.html"></iframe>

<form onsubmit="test(this.elements[0].foo); return false">
<input type="submit" name="fdsa">
<div id=result>FAIL: Test didn't run. Please click on the button above.</div>
</form>