chromium/chrome/test/data/extensions/api_test/messaging/connect_fenced_frames/manifest.json

{
  "name": "connect_external",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Tests connect from a content script.",
  "permissions": ["tabs", "webNavigation"],
  "background": {
    "persistent": false,
    "scripts": ["test.js"]
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
         "http://*/*fenced_frame.html"
      ],
      "js": ["content_script.js"]
    }
  ]
}