cef/libcef/common/service_manifests/renderer_manifest_overlay.json

{
  "name": "content_renderer",
  "interface_provider_specs": {
    "service_manager:connector": {
      "provides": {
        "browser": [
          "spellcheck::mojom::SpellChecker"
        ]
      },
      "requires": {
        "chrome": [ "renderer" ]
      }
    }
  }
}