Speed control of HTML5 video

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "__MSG_name__",
  "description": "__MSG_description__",
  "default_locale": "en",
  "manifest_version": 2,
  "version": "3.1",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "cookies"
  ],
  "options_page": "options.html",
  "browser_action": {
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon38.png",
      "48": "icons/icon48.png"
    },
    "default_popup": "popup.html"
  },
  "background": {
    "persistent": true,
    "scripts": [
      "bg.js"
    ]
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "<all_urls>"
      ],
      "match_about_blank": true,
      "exclude_matches": [
        "https://plus.google.com/hangouts/*",
        "https://hangouts.google.com/*",
        "https://meet.google.com/*",
        "https://teamtreehouse.com/*",
        "http://www.hitbox.tv/*"
      ],
      "css": [
        "inject.css"
      ],
      "js": [
        "inject.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "inject.css",
    "shadow.css"
  ]
}