Examine source code of YouTube Media Controls

{
  "manifest_version": 2,
  "name": "YouTube Media Controls",
  "version": "1.9",
  "description": "Control YouTube player from any tab",
  "content_scripts": [
    {
      "js": [
        "js/utils.js",
        "js/page.js",
        "js/content.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "images/yt-media-controls-logo-16.png",
      "48": "images/yt-media-controls-logo-48.png"
    },
    "default_title": "YouTube Media Controls"
  },
  "icons": {
    "48": "images/yt-media-controls-logo-48.png",
    "128": "images/yt-media-controls-logo-128.png"
  },
  "permissions": [
    "storage",
    "tabs",
    "*://*.youtube.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{378affc0-b1bc-4aeb-90c5-a305f304e53c}"
    }
  }
}