Examine source code of Date Picker Disable

{
  "manifest_version": 2,
  "name": "Disable Date Picker",
  "version": "1.0",
  "description": "Removes HTML date picker from all websites.",
  "permissions": [
    "<all_urls>"
  ],
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "disable-datepicker@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}