Examine source code of Dawdle Block

{
  "manifest_version": 2,
  "name": "Dawdle Block",
  "short_name": "Dawdle Block",
  "description": "Put time limits on unproductive sites.",
  "version": "1.5.2",
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true,
    "browser_style": false
  },
  "browser_action": {
    "default_icon": "images/icon.png",
    "default_popup": "popup.html",
    "default_title": "Dawdle Block"
  },
  "icons": {
    "128": "images/icon.png"
  },
  "permissions": [
    "https://www.googleapis.com/youtube/v3/",
    "https://fonts.googleapis.com/",
    "storage",
    "tabs",
    "alarms"
  ],
  "optional_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "libraries/fflate.min.js",
      "js/bg.js"
    ]
  }
}