Examine source code of Web Video Speed Controller

{
  "name": "Web Video Speed Controller",
  "version": "3.1.1",
  "manifest_version": 2,
  "description": "Effortlessly control any online video speed. Easily operable via floating interface, or keyboard shortcuts, or mouse actions only.",
  "homepage_url": "https://github.com/aynorway",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "options_ui": {
    "page": "src/option/options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "page_action": {
    "default_title": "Control speed of the youtube playback using a keyboard.",
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon38.png"
    },
    "default_popup": "src/option/popup.html"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "http://www.youtube.com/*",
        "https://www.youtube.com/*",
        "<all_urls>"
      ],
      "css": [
        "css/inject.css"
      ],
      "js": [
        "src/inject/inject.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{cfd7cc14-ef7c-4044-8b3d-06110d1ab378}"
    }
  }
}