chromium/third_party/blink/web_tests/fast/frames/iframe-scrolling-attribute.html

<style>
    iframe {
        width: 200px;
        height: 200px;
    }
</style>

<p>This page tests the behavior of the <tt>scrolling</tt> attribute on
<tt>&lt;iframe&gt;</tt> elements which contain a page large enough to need to
be scrolled.</p>

<iframe src="resources/big-page.html"></iframe>
<iframe src="resources/big-page.html" scrolling></iframe>
<iframe src="resources/big-page.html" scrolling=""></iframe>
<iframe src="resources/big-page.html" scrolling="auto"></iframe>
<iframe src="resources/big-page.html" scrolling="yes"></iframe>
<iframe src="resources/big-page.html" scrolling="no"></iframe>
<iframe src="resources/big-page.html" scrolling="bogus"></iframe>
<iframe src="resources/big-page.html" scrolling="1234"></iframe>