Examine source code of AddToCart

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "AddToCart",
  "version": "1.0.0",
  "manifest_version": 2,
  "description": "Temp",
  "homepage_url": "https://reddit.com/u/regexr",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_title": "AddToCart"
  },
  "permissions": [
    "https://www.hottopic.com/*",
    "https://www.boxlunch.com/*",
    "http://www.hottopic.com/*",
    "http://www.boxlunch.com/*",
    "activeTab"
  ]
}