Examine source code of Mute YouTube ads

{
  "manifest_version": 2,
  "name": "Mute Youtube ads",
  "version": "1.0.1",
  "description": "Mutes any www.youtube.com tab when it detects video ads on it. Unmutes the tab when the ads are gone. Backs out on tabs where you manually change the muted state of the tab.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{300093b8-50be-4539-989d-f1c475076a5c}"
    }
  }
}