Death to comments!

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Death to comments!",
  "description": "Banish comments from your internet",
  "version": "0.1",
  "permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "contentscript.js"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ]
}