Zoom on doubleclick

manifest.json

{
  "update_url": "http://clients2.google.com/service/update2/crx",
  "name": " Zoom on doubleclick",
  "version": "0.1.1",
  "manifest_version": 2,
  "description": "Zooming in on websites. Doubleclick on any element on this page to zoom in and doubleclick again, or use ESC, to zoom out.",
  "homepage_url": "http://m-software.de",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "default_locale": "en",
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "src/inject/inject.js",
        "js/jquery-1.8.3.min.js",
        "src/zoom.js"
      ]
    }
  ]
}