chromium/chrome/test/data/extensions/api_test/webrequest/policy_blocked/manifest.json

{
  "name": "Web Request Policy Tests",
  "version": "1",
  "manifest_version": 2,
  "permissions": ["webRequest", "<all_urls>"],
  "background" : {
    "scripts": ["background.js"],
    "persistent": true
  }
}