Examine source code of Javascript Firewall

{
  "manifest_version": 2,
  "name": "Javascript Firewall",
  "version": "1.4",
  "description": "Block JavaScript of unwanted origin.",
  "browser_specific_settings": {
    "gecko": {
      "id": "javascript_firewall@example.com"
    }
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking",
    "webNavigation",
    "*://*/*"
  ],
  "browser_action": {
    "default_icon": "icons/icon.svg",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  }
}