Examine source code of Force Google Locale

{
  "name": "Force Google Locale",
  "description": "Firefox extension that forces the locale of Google sites through the URL",
  "author": "Dietrich Ayala",
  "version": "1.1.0",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{b1d7aa21-850f-445f-8db1-15e43054998c}"
    }
  }
}