Examine source code of Restrict Search Results

{
  "manifest_version": 2,
  "name": "Restrict Search Results",
  "version": "1.0",
  "description": "This extension restricts search results to exclude the top one million most popular websites.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking"
  ],
  "web_accessible_resources": [
    "top-websites.json"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0c0a575b-1339-4086-b2ad-2cd1271ae1d7}"
    }
  }
}