Examine source code of bookmarkpage

{
  "name": "bookmarkpage",
  "version": "1.8.1",
  "manifest_version": 2,
  "description": "show bookmarks in newtab page",
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png"
  },
  "permissions": [
    "tabs",
    "bookmarks"
  ],
  "omnibox": {
    "keyword": "bm"
  },
  "chrome_url_overrides": {
    "newtab": "bookmarkpage.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/32.png",
    "default_title": "add this tab to bookmark"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d3c9f279-21bb-4bae-be22-fbc3dced3eb8}"
    }
  }
}