Examine source code of Default To Bookmarks Menu

{
  "manifest_version": 2,
  "name": "Default To Bookmarks Menu",
  "description": "Set the default bookmark location to the Bookmarks Menu.",
  "author": "QFox",
  "version": "1.0.0",
  "permissions": [
    "bookmarks"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "bookmark-star-on-tray.svg"
  },
  "page_action": {
    "default_icon": {
      "16": "bookmark-star-on-tray.svg"
    }
  }
}