chromium/chrome/test/data/web_apps/mover/index.html

<!DOCTYPE html>

<head>
  <title id="title">App Migration Tester</title>
  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
  <meta content="utf-8" http-equiv="encoding">
</head>

<h1>
  App Migration Tester
</h1>
<p>
  This website can be used to test the web app mover code.
</p>

<div>
  To use this test site, launch Chromium with the following command line
  arguments:
  <pre>--enable-features=MoveWebApp:uninstallStartUrlPrefix/<span id="prefixUrl"></span>/installStartUrl/<span id="installUrl"></span></pre>

  (or customize the URL prefix and install URL here)
  <div>
    <label for="urlPrefixInput">URL Prefix</label>
    <input type="text" id="urlPrefixInput" name="urlPrefixInput" size="100" />
    <label for="installUrlInput">Install URL</label>
    <input type="text" id="installUrlInput" name="installUrlInput" size="100" />
  </div>
</div>

<p>
  This is just the root page, not a web app.
</p>

<div style="border: solid 1px grey; margin: 5px; padding: 5px;">
  Directory:
  <ul>
    <li><a href="migrate_from/a/index.html">migrate_from/a/index.html</a></li>
    <li><a href="migrate_from/b/index.html">migrate_from/b/index.html</a></li>
    <li><a href="migrate_from/c/index.html">migrate_from/c/index.html</a></li>
    <li><a href="migrate_to/index.html">migrate_to/index.html</a></li>
    <li><a href="index.html">index.html (here)</a></li>
  </ul>
</div>

<script>
  function createFeatureParam(str) {
    return str.replace(/[.%\/,:]/g, function(c) {
      return "%" + c.charCodeAt(0).toString(16);
    });
  }
  function updateCommandLine(prefix, installUrl) {
    document.getElementById("prefixUrl").innerHTML = createFeatureParam(prefix);
    document.getElementById("installUrl").innerHTML = createFeatureParam(
      installUrl
    );
  }
  function updateCommandLineFromForm() {
    updateCommandLine(urlPrefixInput.value, installUrlInput.value);
  }
  var urlPrefixInput = document.getElementById("urlPrefixInput");
  var installUrlInput = document.getElementById("installUrlInput");

  urlPrefixInput.addEventListener("change", updateCommandLineFromForm);
  installUrlInput.addEventListener("change", updateCommandLineFromForm);

  var href_without_file = window.location.href;
  href_without_file =
    href_without_file.substring(0, href_without_file.lastIndexOf("/")) + "/";
  var prefixUrl = href_without_file + "migrate_from/";
  var installUrl = href_without_file + "migrate_to/index.html";

  urlPrefixInput.value = prefixUrl;
  installUrlInput.value = installUrl;

  updateCommandLineFromForm();
</script>