Examine source code of xkcd webcomic

{
  "theme": {
    "images": {
      "theme_frame": "xkcdtop.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "xkcd webcomic",
  "manifest_version": 2,
  "description": "Based on the xkcd webcomic by Randall Munroe. <a href=\"https://outgoing.prod.mozaws.net/v1/3bec856f2a70d58682534c164e2c7deb6563dc4e2e8646cb3711755481976b83/http%3A//www.xkcd.com\" rel=\"nofollow\">http://www.xkcd.com</a>"
}