Examine source code of Cookie Deleter

{
  "manifest_version": 2,
  "name": "Cookie Deleter",
  "version": "1.0",
  "description": "Quickly delete cookies, localStorage, and cache for the current site.",
  "author": "Joseph Mitchell",
  "permissions": [
    "cookies",
    "browsingData",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Cookie Deleter",
    "default_icon": "icons/icon128.png"
  },
  "icons": {
    "48": "icons/icon48.png",
    "64": "icons/icon64.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "applications": {
    "gecko": {
      "id": "{e260b8d1-d563-47f4-98e3-9f3e2cd68ab5}",
      "strict_min_version": "68.0"
    }
  }
}