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

{
  "name": "chrome.mediaGalleries.media_metadata",
  "manifest_version": 2,
  "version": "0.1",
  "description": "test chrome.mediaGalleries.getMetadata",
  "app": {
    "background": {
      "scripts": ["test.js"]
    }
  },
  "permissions": [{"mediaGalleries": ["read", "allAutoDetected"]}]
}