chromium/chrome/test/data/extensions/api_test/window_open/browser_is_app/manifest.json

{
  "name": "Browser Is App For Popups Test",
  "version": "1",
  "manifest_version": 2,
  "description": "Browser instance for popups created with window.open() from an extension should return true for is_app()",
  "background": {
    "scripts": ["background.js"]
  },
  "permissions": ["tabs"]
}