Examine source code of QR Code Share

{
  "manifest_version": 2,
  "name": "QR Code Share",
  "version": "1.0",
  "description": "Show QR code for current url",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "page_action": {
    "default_icon": {
      "16": "icons/qr-16.png",
      "48": "icons/qr-48.png",
      "128": "icons/qr-128.png"
    },
    "default_title": "Show QR Code",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "icons/qr-16.png",
    "48": "icons/qr-48.png",
    "128": "icons/qr-128.png"
  },
  "content_security_policy": "script-src 'self'; object-src 'self';",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a7272980-2b62-4581-837b-b6d70c536950}"
    }
  }
}