Examine source code of Custom Homepage Redirect

{
  "manifest_version": 2,
  "name": "Custom Homepage Redirect",
  "version": "1.0",
  "description": "Set a custom homepage and redirect to it on new tab.",
  "permissions": [
    "storage",
    "tabs"
  ],
  "chrome_url_overrides": {
    "newtab": "redirect.html"
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5472091c-dcb9-4a19-9bee-2635019a7b4a}"
    }
  }
}