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

{
   "name": "PageAction Test",
   "manifest_version": 2,
   "version": "1.0",
   "page_action": {
      "default_icon": "image1.png",
      "default_popup": "a_popup.html",
      "default_title": "MyExtensionActionTitle"
   }
}