Custom emoticons

manifest.json

{
  "update_url": "http://clients2.google.com/service/update2/crx",
  "name": "Custom emoticons",
  "version": "3",
  "manifest_version": 2,
  "description": "custom emoticons on facebook",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.facebook.com/*"
      ],
      "run_at": "document_idle",
      "all_frames": true,
      "js": [
        "script.js"
      ]
    }
  ]
}