Examine source code of File Upload

{
  "manifest_version": 2,
  "name": "File Upload",
  "version": "1.0.0",
  "description": "网页打开文件选择器前先弹出确认提示，确认后才允许继续。",
  "permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-script.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "page-bridge.js",
    "upload-guide.svg",
    "upload-guide-final.svg"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "confir-file-upload@example.local",
      "strict_min_version": "91.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}