Examine source code of MasterCook

{
  "name": "MasterCook",
  "version": "3.0.6",
  "description": "MasterCook Recipe Analytics, Meal Planning & Storage",
  "manifest_version": 2,
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_action": {
    "default_icon": "assets/images/MasterCookLogo-small.png",
    "default_popup": "index.html"
  },
  "icons": {
    "16": "assets/images/MasterCookLogo-small.png",
    "32": "assets/images/MasterCookLogo-small.png",
    "48": "assets/images/MasterCookLogo-small.png",
    "128": "assets/images/MasterCookLogo-small.png"
  },
  "permissions": [
    "activeTab",
    "https://www.mastercook.com/",
    "https://staging.mastercook.com/",
    "http://staging.mastercook.com/",
    "https://qa.mastercook.com/",
    "http://qa.mastercook.com/",
    "http://api.mastercook.com/",
    "https://api.mastercook.com/",
    "http://*/",
    "contextMenus",
    "clipboardWrite",
    "clipboardRead"
  ],
  "background": {
    "persistent": true,
    "page": "background.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5d71b0bc-7416-4bd7-a74c-b0405f427b97}"
    }
  }
}