Examine source code of FbChat

{
  "manifest_version": 2,
  "name": "FbChat",
  "version": "1.4",
  "content_scripts": [
    {
      "matches": [
        "https://m.facebook.com/*"
      ],
      "js": [
        "FbChat.js"
      ]
    }
  ],
  "applications": {
    "gecko": {
      "id": "jquezadarios@gmail.com",
      "strict_min_version": "45.0"
    }
  },
  "permissions": [
    "https://m.facebook.com/*",
    "https://stackpath.bootstrapcdn.com/*",
    "webRequest",
    "webRequestBlocking"
  ],
  "background": {
    "scripts": [
      "BackgroundScript.js"
    ]
  }
}