chrome/test/data/extensions/api_test/media_galleries/access_attached/manifest.json

{
  "name": "chrome.mediaGalleries.access_attached",
  "manifest_version": 2,
  "version": "0.1",
  "description": "test access of attached storage for chrome.mediaGalleries.getMediaFileSystems",
  "app": {
    "background": {
      "scripts": ["test.js"]
    }
  },
  "permissions": [{"mediaGalleries": ["read", "allAutoDetected"]}]
}