chromium/chrome/test/data/extensions/api_test/content_scripts/extension_iframe/manifest.json

{
  "name": "content_script_extension_iframe",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Tests that a chrome-extension iframe gets messaging privileges",
  "background": {
    "scripts": ["test.js"],
    "persistent": true
  },
  "permissions": ["tabs", "bookmarks", "storage"],
  "content_scripts": [
    {
      "matches": ["http://*/*"],
      "js": ["script.js"]
    }
  ],
  "web_accessible_resources": [
    "iframe.html",
    "iframe.js"
  ]
}