chrome/test/data/extensions/platform_apps/context_menu/manifest.json

{
  "name" : "Platform App Context Menus Test Extension",
  "manifest_version": 2,
  "version" : "0.1",
  "permissions": [
    "contextMenus"
  ],
  "app": {
    "background": {
      "scripts": ["test.js"]
    }
  }
}