extensions/test/data/system/storage/manifest.json

{
  "name": "storage info",
  "version": "0.1",
  "manifest_version": 2,
  "description": "Test system.storage API",
  "permissions": ["system.storage"] ,
  "app": {
    "background": {
      "scripts": ["test_storage_api.js"]
    }
  }
}