Examine source code of Mega低調碼

{
  "manifest_version": 2,
  "name": "Mega低調碼",
  "description": "『Mega低調碼』解碼神還原～支援0rz.tw/tinyurl.com等短網址！",
  "version": "1.1.0",
  "permissions": [
    "http://0rz.tw/*",
    "https://tinyurl.com/*",
    "contextMenus",
    "tabs"
  ],
  "browser_action": {
    "default_title": "Mega低調碼",
    "default_icon": {
      "16": "images/icon16.png",
      "48": "images/icon48.png",
      "128": "images/icon128.png"
    },
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "background": {
    "scripts": [
      "event.js"
    ],
    "persistent": true
  }
}