Examine source code of Refresh Your Bookmarks

{
  "manifest_version": 2,
  "name": "Refresh Your Bookmarks",
  "version": "0.4.1resigned1",
  "description": "Update your bookmarks when pages have been moved or deleted",
  "author": "Robert Rothenberg",
  "homepage_url": "https://github.com/robrwo/bookmarks-refresh-firefox",
  "icons": {
    "48": "icons/link.svg",
    "96": "icons/link.svg"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "bookmarks",
    "activeTab",
    "webRequest",
    "notifications",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e53033bc-0678-463a-82ea-d9610dafdad0}"
    }
  }
}