Facepie

manifest.json

{
  "update_url": "http://clients2.google.com/service/update2/crx",
  "name": "Facepie",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Makes all profile pictures on Facebook as round as a pie!",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "incognito": "spanning",
  "offline_enabled": true,
  "permissions": [
    "tabs",
    "https://*.facebook.com/",
    "http://*.facebook.com/"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*.facebook.com/*",
        "https://*.facebook.com/*",
        "http://facebook.com/*",
        "https://facebook.com/*"
      ],
      "css": [
        "facepie.css"
      ]
    }
  ]
}