Examine source code of Checker Mail.ru

{
  "background": {
    "page": "background.html"
  },
  "browser_action": {
    "default_icon": {
      "16": "img/icon-16.png",
      "32": "img/icon-32.png",
      "48": "img/icon-48.png",
      "128": "img/icon-128.png"
    },
    "default_title": "__MSG_name__",
    "default_popup": "popup.html"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "default_locale": "ru",
  "description": "__MSG_description__",
  "icons": {
    "16": "img/icon-16.png",
    "32": "img/icon-32.png",
    "48": "img/icon-48.png",
    "64": "img/icon-64.png",
    "96": "img/icon-96.png",
    "128": "img/icon-128.png"
  },
  "manifest_version": 2,
  "name": "__MSG_name__",
  "options_page": "options.html",
  "permissions": [
    "notifications",
    "storage",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "https://mail.ru/*",
    "https://www.mail.ru/*",
    "https://e.mail.ru/*",
    "https://auth.mail.ru/*",
    "https://touch.mail.ru/*",
    "https://filin.mail.ru/*",
    "https://portal.mail.ru/*",
    "https://mailru-checker-api.e.mail.ru/*"
  ],
  "short_name": "__MSG_short_name__",
  "version": "1.7.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "mailru-checker@custom",
      "strict_min_version": "126.0"
    }
  }
}