chromium/chrome/test/data/extensions/api_test/content_scripts/inject_div/manifest.json

{
  "manifest_version": 2,
  "name": "Script injects div",
  "version": "0.1",
  "description": "Injects a div using its content script",
  "content_scripts": [{
    "matches": ["*://*/*"],
    "js": ["script.js"],
    "all_frames": true,
    "run_at": "document_end"
  }]
}