chromium/extensions/test/data/manifest_tests/page_action_manifest_version_2b.json

{
  "manifest_version": 2,
  "name": "my extension",
  "version": "1.0.0.0",
  "description": "The page_action.popup value cannot be an object in manifest_version 2.",
  "page_action": {
    "default_popup": {
    }
  }
}