Google Forms Image Viewer

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Google Forms Image Viewer",
  "version": "1.0",
  "description": "a tool to allow image files to be viewed on a google form response",
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "https://docs.google.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "printing.css"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_popup": "popup.html"
  }
}