Examine source code of YouTube Control Center

{
  "name": "YouTube Control Center",
  "short_name": "iycc",
  "description": "YouTube popup pause and resume as well as no buffer, HD quality, wide screen, ...",
  "author": "InBasic",
  "version": "0.6.4resigned1",
  "manifest_version": 2,
  "permissions": [
    "storage",
    "tabs",
    "cookies",
    "*://*.youtube.com/*"
  ],
  "background": {
    "persistent": false,
    "scripts": [
      "common.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "data/page.js",
        "data/controls.js",
        "data/no_buffer.js",
        "data/quality.js",
        "data/next_track.js",
        "data/css.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "icons": {
    "16": "data/icons/16.png",
    "32": "data/icons/32.png",
    "48": "data/icons/48.png",
    "64": "data/icons/64.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "data/icons/16.png",
      "32": "data/icons/32.png",
      "48": "data/icons/48.png",
      "64": "data/icons/64.png"
    },
    "default_title": "YouTube Control Center\n\n-> Opens YouTube when no player is detected.\n-> Displays the control popup when there is at least one YouTube player"
  },
  "homepage_url": "http://add0n.com/control-center.html",
  "commands": {
    "pause": {
      "description": "Stat the player"
    },
    "stop": {
      "description": "Stop the player"
    },
    "play": {
      "description": "Pause the player"
    },
    "next": {
      "description": "Move to the next track"
    },
    "previous": {
      "description": "Move to the previous track"
    }
  },
  "applications": {
    "gecko": {
      "id": "jid1-CikLKKPVkw6ipw@jetpack",
      "strict_min_version": "57.0"
    }
  }
}