Examine source code of HAR File Viewer

{
  "manifest_version": 2,
  "name": "HAR File Viewer",
  "version": "1.0",
  "description": "View and analyze .har network log files directly in the browser.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{54ffb350-1a86-4dab-afef-7f015e9a35a7}"
    }
  }
}