Examine source code of XPath Helper for developer

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "XPath Helper for developer",
  "version": "2.0.5",
  "description": "Extract, edit, and evaluate XPath queries with ease. this fork from https://github.com/google/xpaf",
  "background": {
    "page": "background.html"
  },
  "browser_action": {
    "default_icon": {
      "38": "static/xpath.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "content.css"
      ],
      "js": [
        "xpath-patch.js",
        "content.js"
      ]
    }
  ],
  "icons": {
    "32": "static/xpath.png",
    "48": "static/xpath.png",
    "128": "static/xpath.png"
  },
  "web_accessible_resources": [
    "bar.css",
    "bar.html",
    "bar.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1e38ce2c-3565-4b1c-b3c7-aee41dd35dd9}"
    }
  }
}