Examine source code of Offline Webpages

{
  "manifest_version": 2,
  "name": "Offline Webpages",
  "version": "4.3",
  "description": "Save and access fully formatted web pages offline within the extension.",
  "icons": {
    "16": "iconoff.jpg",
    "48": "iconoff.jpg",
    "128": "iconoff.jpg"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "iconoff.jpg"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9fd43bd3-103b-442b-ab82-bcef1a963eb0}"
    }
  }
}