chromium/chrome/test/data/banners/manifest_too_small_icon.json

{
  "name": "Manifest test app",
  "icons": [
    {
      "src": "launcher-icon-1x.png",
      "sizes": "48x48",
      "type": "image/png",
      "purpose": "any monochrome"
    }
  ],
  "start_url": "manifest_test_page.html",
  "display": "standalone",
  "orientation": "landscape"
}