Examine source code of CommentAnywhere.org for Facebook and VKontakte

{
  "description": "CommentAnywhere.org allows you to comment anywhere on the web using your Facebook account.",
  "manifest_version": 2,
  "name": "CommentAnywhere.org",
  "version": "1.3.1",
  "homepage_url": "http://www.commentanywhere.org",
  "icons": {
    "16": "icon_16x16.png",
    "32": "icon_32x32.png",
    "48": "icon_48x48.png",
    "128": "icon_128x128.png"
  },
  "applications": {
    "gecko": {
      "id": "commentanywhere@commentanywhere.org",
      "strict_min_version": "40.*"
    }
  },
  "permissions": [
    "alarms",
    "activeTab",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "http://chrome.commentanywhere.org/*"
  ],
  "page_action": {
    "default_icon": "icon_32x32.png",
    "default_title": "CommentAnywhere.org",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}