chromium/chrome/test/data/extensions/platform_apps/web_view/extension_api/component_extension/script.js

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

chrome.runtime.onMessageExternal.addListener(
    function(message, sender, callback) {
  if (typeof sender.guestProcessId !== 'undefined' &&
      typeof sender.guestRenderFrameRoutingId !== 'undefined') {
    callback({
      result: 'defined',
      guestProcessId: sender.guestProcessId,
      guestRenderFrameRoutingId: sender.guestRenderFrameRoutingId
    });
  } else {
    callback({result: 'undefined'});
  }
});