Examine source code of chrismas countdown

{
  "manifest_version": 2,
  "name": "chrismas countdown",
  "description": "countdown till chrismas",
  "version": "1.0.0",
  "icons": {
    "64": "icons/icon.png"
  },
  "background": {
    "scripts": [
      "background_script.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "64": "icons/icon.png"
    },
    "default_popup": "browserAction/index.html",
    "default_title": "translate"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{90acb4fb-c339-447d-aaf0-f05909682b52}"
    }
  }
}