Examine source code of URL Phishing Shield

{
  "manifest_version": 2,
  "name": "URLPhishingShield",
  "version": "1.2",
  "description": "Search directly typed URLs using the default search engine",
  "icons": {
    "16": "icons/urlicon_16.png",
    "48": "icons/urlicon_48.png",
    "128": "icons/urlicon_128.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "<all_urls>",
    "search"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "directurltoduckduckgo@example.com",
      "strict_min_version": "111.0"
    }
  }
}