Examine source code of Bookmark Multiple URLs

{
  "manifest_version": 2,
  "name": "Bookmark Manager",
  "version": "1.0",
  "description": "Add bookmarks from a list of URLs",
  "permissions": [
    "bookmarks"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{91580404-89e7-4602-8bf3-129fd81045e0}"
    }
  }
}