Examine source code of HTTP Headers Viewer

{
  "manifest_version": 2,
  "name": "HTTP Headers Viewer",
  "version": "1.1",
  "description": "Displays the HTTP headers of the current page.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png"
    },
    "default_title": "HTTP Headers Viewer"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "icons/icon-48.png",
    "icons/icon-96.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{eeffc55d-d4fd-4fe9-8bb4-3abc8e148e10}"
    }
  }
}