Examine source code of Large Notification Center

{
  "manifest_version": 2,
  "name": "Large Notification Center",
  "version": "1.0",
  "description": "One easy-to-read center for all site notifications.",
  "permissions": [
    "notifications",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Notification Center"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d5108b2d-a9ee-4a7b-a458-808a90ee3eb3}"
    }
  }
}