Examine source code of Desktop Notif

{
  "manifest_version": 2,
  "name": "__MSG_gs_chrome__",
  "short_name": "GS Chrome",
  "description": "__MSG_manifest_description__",
  "version": "11.1",
  "default_locale": "en",
  "author": "Yuri Konotopov <ykonotopov@gnome.org>",
  "key": "${PUBLIC_KEY}",
  "icons": {
    "16": "icons/GnomeLogo-16.png",
    "48": "icons/GnomeLogo-48.png",
    "128": "icons/GnomeLogo-128.png"
  },
  "background": {
    "scripts": [
      "include/i18n.js",
      "include/constants.js",
      "include/compat-common.js",
      "include/gsc.js",
      "include/notifications.js",
      "include/update.js",
      "include/sync.js",
      "include/toolbar.js",
      "extension.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/GnomeLogo-16.png",
      "32": "icons/GnomeLogo-32.png"
    },
    "default_title": "__MSG_open_website__"
  },
  "content_scripts": [
    {
      "matches": [
        "https://extensions.gnome.org/*"
      ],
      "run_at": "document_start",
      "js": [
        "include/constants.js",
        "include/compat-content-script.js",
        "content-script-start.js"
      ]
    }
  ],
  "externally_connectable": {
    "matches": [
      "https://extensions.gnome.org/*"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  },
  "permissions": [
    "alarms",
    "nativeMessaging",
    "notifications",
    "storage",
    "https://extensions.gnome.org/"
  ],
  "optional_permissions": [
    "idle"
  ],
  "web_accessible_resources": [
    "include/sweettooth-api.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{926e9dd4-0e50-4217-b99d-d7a82ceadddf}"
    }
  }
}