If you have more than one copy of React DevTools installed and enabled (e.g. the version in the Chrome store and a locally built version) they can interfere with each other.

DevTools should detect this case and warn by showing a dialog in the DevTools UI and/or by logging to the console.

Note that we _should not warn_ if a related tool like Fast Refresh is present, only another copy of DevTools.
one.postMessage(message);
  }
  function shutdown() {
    one.onMessage.removeListener(lOne);
    two.onMessage.removeListener(lTwo);
    one.disconnect();
    two.disconnect();
  }
  one.onDisconnect.addListener(shutdown);
  two.onDisconnect.addListener(shutdown);
}
function setIconAndPopup(reactBuildType, tabId) {
  chrome.browserAction.setIcon({
    tabId: tabId,
    path: {
      '16': 'icons/16-' + reactBuildType + '.png',
      '32': 'icons/32-' + reactBuildType + '.png',
      '48': 'icons/48-' + reactBuildType + '.png',
      '128': 'icons/128-' + reactBuildType + '.png',
    },
  });
  chrome.browserAction.setPopup({
    tabId: tabId,
    popup: 'popups/' + reactBuildType + '.html',
  });
}
function isRestrictedBrowserPage(url) {
  return !url || new URL(url).protocol === 'chrome:';
}
function checkAndHandleRestrictedPageIfSo(tab) {