Examine source code of Speeder

{
  "name": "Speeder",
  "short_name": "Speeder",
  "version": "5.3.0",
  "manifest_version": 2,
  "description": "Speed up, slow down, advance and rewind HTML5 audio/video with shortcuts (New and improved version of \"Video Speed Controller\")",
  "homepage_url": "https://github.com/SoPat712/speeder",
  "browser_specific_settings": {
    "gecko": {
      "id": "{ed860648-f54f-4dc9-9a0d-501aec4313f5}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "https://cdn.jsdelivr.net/*"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon38.png",
      "48": "icons/icon48.png"
    },
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "http://*/*",
        "https://*/*",
        "file:///*"
      ],
      "match_about_blank": true,
      "exclude_matches": [
        "https://plus.google.com/hangouts/*",
        "https://hangouts.google.com/*",
        "https://meet.google.com/*"
      ],
      "css": [
        "inject.css"
      ],
      "js": [
        "shared/controller-utils.js",
        "shared/key-bindings.js",
        "shared/site-rules.js",
        "ui-icons.js",
        "inject.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "inject.css",
    "shadow.css"
  ]
}