chromium/chrome/test/data/extensions/api_test/serial/real_hardware/manifest.json

{
  "name": "chrome.serial real hardware",
  "manifest_version": 2,
  "version": "0.1",
  "description": "end-to-end real-hardware test for chrome.serial API",
  "app": {
    "background": {
      "scripts": ["background.js"]
    }
  },
  "permissions": [
    "serial"
  ]
}