chromium/chrome/test/data/extensions/api_test/webrequest_persistent/manifest.json

{
  "name": "Web Request Persistence",
  "version": "0.1",
  "manifest_version": 2,
  "background": {
    "scripts": ["background.js"],
    "persistent": true
  },
  "permissions": ["webRequest", "storage", "http://example.com/*"]
}