Examine source code of Large Font Mode

{
  "manifest_version": 2,
  "name": "Large Font Mode",
  "version": "1.0",
  "description": "Instantly enlarge all text.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_title": "Large Font Mode",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8c7adc87-6939-4246-9933-eeb0e43f010a}"
    }
  }
}