Examine source code of Audio Player

{
  "manifest_version": 2,
  "version": "0.2.6",
  "name": "Audio Player",
  "description": "FFmpeg-based audio player that supports a wide range of audio codecs",
  "permissions": [
    "storage",
    "contextMenus",
    "fileBrowserHandler",
    "*://*/*"
  ],
  "icons": {
    "16": "/data/icons/16.png",
    "32": "/data/icons/32.png",
    "48": "/data/icons/48.png",
    "64": "/data/icons/64.png",
    "128": "/data/icons/128.png",
    "256": "/data/icons/256.png",
    "512": "/data/icons/512.png"
  },
  "background": {
    "scripts": [
      "/v2/chrome.action.js",
      "/v2/chrome.contextMenus.create.js",
      "/v2/chrome.runtime.js",
      "/v2/chrome.windows.create.js",
      "/v2/chrome.windows.get.js",
      "/v2/chrome.windows.getCurrent.js",
      "worker.js"
    ]
  },
  "content_security_policy": "script-src 'self' 'wasm-unsafe-eval'; object-src 'self'",
  "homepage_url": "https://webextension.org/listing/audio-player.html",
  "commands": {
    "_execute_browser_action": {}
  },
  "file_browser_handlers": [
    {
      "id": "open-media",
      "default_title": "Open with Audio Player",
      "file_filters": [
        "filesystem:*.avi",
        "filesystem:*.mp4",
        "filesystem:*.webm",
        "filesystem:*.flv",
        "filesystem:*.mov",
        "filesystem:*.ogv",
        "filesystem:*.3gp",
        "filesystem:*.mpg",
        "filesystem:*.wmv",
        "filesystem:*.swf",
        "filesystem:*.mkv",
        "filesystem:*.pcm",
        "filesystem:*.wav",
        "filesystem:*.aac",
        "filesystem:*.ogg",
        "filesystem:*.wma",
        "filesystem:*.flac",
        "filesystem:*.mid",
        "filesystem:*.mka",
        "filesystem:*.m4a",
        "filesystem:*.voc",
        "filesystem:*.mp3"
      ]
    }
  ],
  "browser_action": {},
  "browser_specific_settings": {
    "gecko": {
      "id": "{18988923-610e-46a6-a3e2-eec2baeaadf7}"
    }
  }
}