chromium/third_party/blink/web_tests/fast/forms/plaintext-mode-2.html

<script>
function log(message) {
    var li = document.createElement("li");
    li.appendChild(document.createTextNode(message));
    var console = document.getElementById("console");
    console.appendChild(li);
}

function assert(func, args, expected) {
    var f = func + '("' + args + '")';
    var result = eval(f);
    if (result != expected)
        log('Failure: ' + f + ' was ' + result + ', expected: ' + expected);
    else
        log('Success: ' + f + ' == ' + result);
}
</script>

<input id="textfield" type="text" style="width: 600">
<br>
<div id="richcontent">This <b>styled <i>text</i></b>, and <a href="http://www.google.com"> link</a> will be pasted into the textfield.  All richness should be stripped.</div>
<ol id="console"></ol>
<script>
    if (window.testRunner)
        testRunner.waitUntilDone();

var richcontent = document.getElementById("richcontent");
var s = window.getSelection();
s.setBaseAndExtent(richcontent, 0, richcontent, richcontent.childNodes.length);
assert("document.execCommand", "Copy", true);

var e = document.getElementById("textfield");
e.focus();
e.setSelectionRange(0, 0);

window.setTimeout(paste, 500);
function paste() {
    assert("document.execCommand", "Paste", true);
    if (window.testRunner)
        testRunner.notifyDone();
}
</script>