Giffing

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Giffing",
  "description": "Replace links to images with gifs in Google Hangouts.",
  "version": "0.0.0.2",
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*",
        "http://www.google.com/*",
        "https://hangouts.google.com/webchat/*"
      ],
      "js": [
        "jquery-2.2.3.js",
        "giffing.js"
      ],
      "all_frames": true
    }
  ],
  "icons": {
    "128": "icon128.png"
  }
}