chromium/chrome/test/data/extensions/api_test/window_open/popup_blocking/extension/manifest.json

{
  "name": "Popup blocking test",
  "version": "1",
  "manifest_version": 2,
  "description": "Popup windows should never be blocked from within an extension.",
  "permissions": ["tabs"],
  "background": {
    "scripts": ["pop.js", "background.js"]
  },
  "content_scripts": [
    {
      "matches": ["http://b.com/*"],
      "js": ["pop.js", "content_script.js"]
    }
  ]
}