Examine source code of Font Size Adjuster

{
  "manifest_version": 2,
  "name": "Font Size Adjuster",
  "version": "1.0",
  "description": "Adjust the font size on webpages for better readability.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/adjust-48.png",
    "default_popup": "popup.html",
    "default_title": "Adjust Font Size"
  },
  "icons": {
    "48": "icons/adjust-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0831e12d-fd95-4887-a0db-74c494570848}"
    }
  }
}