Examine source code of Modest Vision

{
  "manifest_version": 2,
  "name": "Modest Vision",
  "description": "This extension blurs inappropriate graphics on some popular websites e.g. Facebook, Youtube, Twitter etc.",
  "version": "1.2resigned1",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Modest Vision"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.youtube.com/*"
      ],
      "css": [
        "css/youtube.css"
      ]
    },
    {
      "matches": [
        "https://*.twitter.com/*"
      ],
      "css": [
        "css/twitter.css"
      ]
    },
    {
      "matches": [
        "https://*.facebook.com/*"
      ],
      "css": [
        "css/facebook.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{dd599d3e-fd6b-4391-b3d1-b90844eb3ed8}"
    }
  }
}