chromium/chrome/test/data/extensions/back_forward_cache/content_script/content_script.js

// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

document.title = "modified";

chrome.runtime.onConnect.addListener((p) => {
  p.postMessage('connected');
  p.onMessage.addListener((m) => {
    if (m == 'disconnect') {
      p.disconnect();
    }
  });
});