Examine source code of XPath Helper VM

{
  "manifest_version": 2,
  "name": "XPath Helper",
  "version": "1.3",
  "description": "Test and evaluate XPath expressions directly on any webpage.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "XPath Helper"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bf159099-3a37-4f35-a412-c922725647fb}"
    }
  }
}