Examine source code of Bookmark 404 Checker

{
  "manifest_version": 2,
  "name": "Bookmark 404 Checker",
  "version": "1.0",
  "description": "Checks bookmarks for 404 errors and removes them.",
  "permissions": [
    "bookmarks",
    "tabs",
    "activeTab",
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{4ed47f85-29f4-4ac9-954f-94a26e43d423}"
    }
  }
}