chromium/chrome/test/data/extensions/platform_apps/web_view/shim/manifest.json

{
  "name": "Platform App Test: <webview>",
  "manifest_version": 2,
  "version": "2",
  "permissions": [
    "webview"
  ],
  "app": {
    "background": {
      "scripts": ["test.js"]
    }
  },
  "webview": {
    "partitions": [
      {
        "name": "foobar",
        "accessible_resources": [
          "child_frame.html",
          "parent_frame.html",
          "guest_with_inline_script.html",
          "test.bmp",
          "test.pdf",
          "pdf_with_dialog.pdf",
          "guest_with_select.html"
        ]
      }
    ]
  }
}