Nextube - The missing next button

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Nextube - The missing next button",
  "short_name": "Nextube",
  "version": "0.9.3",
  "manifest_version": 2,
  "description": "Next button for YouTube",
  "icons": {
    "16": "icons/yn16.png",
    "48": "icons/yn48.png",
    "128": "icons/yn128.png"
  },
  "background": {
    "page": "src/bg/background.html",
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/yn19.png",
      "38": "icons/yn72.png"
    },
    "default_title": "Nextube"
  },
  "commands": {
    "next_song": {
      "suggested_key": {
        "default": "Ctrl+N",
        "mac": "MacCtrl+N"
      },
      "description": "Play Next"
    },
    "pause": {
      "suggested_key": {
        "default": "Ctrl+P",
        "mac": "MacCtrl+P"
      },
      "description": "Play/Pause"
    }
  },
  "permissions": [
    "tabs",
    "contextMenus"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "src/inject/inject.js"
      ]
    }
  ]
}