chromium/chrome/test/data/extensions/api_test/socket/unload/manifest.json

{
  "name": "chrome.socket",
  "manifest_version": 2,
  "version": "0.1",
  "description": "browser test for chrome.socket API to make sure sockets are free'd when extension is reloaded",
  "app": {
    "background": {
      "scripts": ["background.js"]
    }
  },
  "permissions": [
    {"socket": [
      "tcp-listen"
    ]}
  ]
}