chromium/extensions/test/data/manifest_tests/externally_connectable_tld.json

{
  "name": "extensions_unittests --gtest_filter=ExternallyConnectableTest.TLD",
  "version": "1",
  "manifest_version": 2,
  "externally_connectable": {
    "matches": [
      "http://*.co.uk/*"
    ]
  }
}