Examine source code of Website Speed Meter

{
  "manifest_version": 2,
  "name": "Website Speed Meter",
  "version": "1.0.0",
  "description": "Measure and display real-time website loading performance metrics including load time, resource count, and page size",
  "permissions": [
    "activeTab",
    "webNavigation",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "View Website Performance",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "performance.js"
      ],
      "run_at": "document_start"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{eb269518-d69a-4360-9ea4-47d7dd8c1585}"
    }
  }
}