Examine source code of Random Font Changer

{
  "manifest_version": 2,
  "name": "Random Font Changer",
  "version": "1.3",
  "description": "Change the font of any webpage to a random Google Font with one click",
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{77cd4437-de57-402c-8d50-ee783427f29b}"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Change to Random Font"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "options_ui": {
    "page": "settings.html",
    "open_in_tab": true
  }
}