"content_scripts": [ { "matches": ["http:///", "https:///"], "js": ["contents/counter/index.js"], "css": ["contents/counter/index.css"], "run_at": "document_idle", "all_frames": false } ]
https://developer.chrome.com/docs/extensions/mv2/declare_permissions/
https://developer.chrome.com/docs/extensions/reference/#stable_apis