Examine source code of Custom URL for New Tab

{
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "description": "Load a custom URL in new tab.",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhOfPL+5B/RopGNRF5ureMZIVO9vWLfhxfYlLtrvN42ClqSIh/fRVVKjQsEa76R/97yEEP8epzRxLnNg1YJGywHLvTua7Ycb5PDJBLbOaE88cLJ4gSlQQof/Cpl5ESkrNbtaxUoIOIYGXUHufjRfbXqOpBq5W+fmqgUpm1v4X7o2LmJuIJpaXFHuV5ObSj2vIVWxluQNRbodEKbLBPm1EeQR7PGknzOWqd85QJ13nXGI9p1aubQuDwh0LwHk6FpOWXteVvEWwv0xx+Q2Am4MYHmdesBwXBLR+DCWPgHIN327Yr3Vgxuwvjn2S4CWGbIZnGcNgEUd8V02CNBkj3wetIQIDAQAB",
  "manifest_version": 2,
  "name": "New Tab Override",
  "options_page": "options.html",
  "permissions": [
    "storage",
    "http://*/*",
    "https://*/*"
  ],
  "update_url": "https://clients2.google.com/service/update2/crx",
  "version": "1.0.1"
}