Examine source code of Subscribers on comments for YouTube™

{
  "description": "Shows the YouTube subscribers count of each user's comment.",
  "manifest_version": 2,
  "name": "Subscribers on comments for YouTube™",
  "version": "1.3resigned1",
  "homepage_url": "https://github.com/xatok/subscribers-on-comments-for-youtube",
  "background": {
    "scripts": [
      "/js/background.js"
    ]
  },
  "page_action": {
    "browser_style": true
  },
  "icons": {
    "32": "icons/icon-32.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "*://*/*",
    "tabs",
    "contextMenus",
    "webRequest",
    "webRequestBlocking",
    "webNavigation"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "css": [
        "/css/content-style.css"
      ],
      "js": [
        "/js/content-script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{59328c27-6a3c-408e-b59a-6d95a49be90f}"
    }
  }
}