Examine source code of Youtime

{
  "manifest_version": 2,
  "name": "Youtime",
  "description": "track youtube time",
  "version": "0.0.1",
  "content_security_policy": "default-src 'self'; script-src 'self'; object-src 'self';",
  "icons": {
    "48": "icons/icon.png"
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "activeTab",
    "webNavigation"
  ],
  "background": {
    "scripts": [
      "background_script.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "64": "icons/icon.png"
    },
    "default_popup": "browserAction/index.html",
    "default_title": "Youtime"
  },
  "options_ui": {
    "page": "options/index.html"
  }
}