Examine source code of Smart Media Pauser

{
  "manifest_version": 2,
  "name": "Smart Media Pauser",
  "version": "1.0.0",
  "description": "Pause media in the tab when it loses focus.",
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{006cdcf7-6070-4658-9ee5-a0206fac744f}",
      "strict_min_version": "101.0"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ]
}