Examine source code of HTML5 Speed Controller

{
  "manifest_version": 2,
  "name": "HTML5 Speed Controller",
  "version": "1.0",
  "description": "Control the speed of HTML5 video or audio on any page.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "commands": {
    "open-popup": {
      "suggested_key": {
        "default": "Ctrl+Shift+L"
      },
      "description": "Open the popup to adjust speed."
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{abba387b-e1f6-4c7c-a3be-779898bda47c}"
    }
  }
}