chromium/content/test/data/android/type_window_content_changed_events.html

<!-- Simple file to generate many TYPE_WINDOW_CONTENT_CHANGED events. -->
<html>
  <head>
    <script>
      const SCRIPT_COUNT = 50;
      var elementArray = [];

      function expandComboboxes() {
        elementArray.forEach(node => {
          node.setAttribute("aria-expanded", true);
          node.getElementsByTagName('div')[0].removeAttribute('hidden');
        });
        var button = document.getElementsByTagName('button')[0];
        button.innerHTML = "Done";
      }

      function createComboboxes() {
        var body = document.getElementsByTagName('body')[0];
        for (i = 0; i < SCRIPT_COUNT; i++) {
          var containingDiv = document.createElement('div');

          var combobox = document.createElement('div');
          combobox.setAttribute("role", "combobox");
          combobox.setAttribute("aria-expanded", "false");

          var input = document.createElement('input');
          input.setAttribute("type", "text");

          var childDiv = document.createElement('div');
          childDiv.setAttribute("hidden", "");

          var paragraph = document.createElement('p');
          paragraph.innerHTML = "Example Text";

          childDiv.appendChild(paragraph);
          combobox.appendChild(input);
          combobox.appendChild(childDiv);

          containingDiv.appendChild(combobox);
          body.appendChild(containingDiv);

          elementArray[i] = combobox;
        }
      }
    </script>
  </head>
  <body onload="createComboboxes()">
    <button onclick="expandComboboxes()">Expand All</button>
  </body>
</html>