Examine source code of Close All Tabs Button

{
  "name": "Close All Tabs Button",
  "version": "0.3resigned1",
  "manifest_version": 2,
  "description": "Adds close all tabs button. The button opens a new tab and closes all existing tabs.",
  "default_locale": "en",
  "icons": {
    "16": "close_all.png",
    "48": "close_all_48.png",
    "128": "close_all_128.png"
  },
  "browser_action": {
    "default_icon": "close_all.png",
    "default_title": "Close All"
  },
  "background": {
    "scripts": [
      "options.js",
      "close_all.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c6413edf-a84d-4f60-a226-087809b8ae64}"
    }
  }
}