chrome/test/data/extensions/api_test/usb_manual/list_interfaces/manifest.json

{
  "name": "USB Manual List Interface",
  "manifest_version": 2,
  "version": "0.1",
  "app": {
    "background": {
      "scripts": ["test.js"]
    }
  },
  "permissions": [
    "usb"
  ],
  "optional_permissions": [
    {"usbDevices": [
      {"vendorId": 6353, "productId": 20194}
    ]}
  ]
}