chromium/chrome/test/data/extensions/api_test/override/newtab_upgrade/manifest.json

{
  "name": "New tab override test, number 1",
  "version": "0.2",
  "manifest_version": 2,
  "description": "Test chrome://newtab override",
  "permissions": [
    "tabs"
  ],
  "chrome_url_overrides": {
    "newtab": "newtab_upgrade.html"
  }
}