chrome/common/extensions/docs/examples/api/document_scan/manifest.json

{
  "name": "Document Scanning API Sample",
  "version": "0.1",
  "manifest_version": 2,
  "minimum_chrome_version": "37",
  "app": {
    "background": {
      "scripts": ["background.js"]
    }
  },
  "permissions": [],
  "optional_permissions": [ "documentScan" ]
}