Examine source code of Multi-highlight

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Multi-highlight",
  "description": "Search and highlight multiple words on web pages.",
  "version": "1.20",
  "icons": {
    "19": "img/19x19.png",
    "48": "img/48x48.png",
    "100": "img/100x100.png",
    "128": "img/128x128.png"
  },
  "permissions": [
    "tabs",
    "http://*/*",
    "https://*/*",
    "storage"
  ],
  "background": {
    "scripts": [
      "js/jquery.js",
      "js/background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "img/19x19.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ],
      "all_frames": true,
      "css": [
        "css/highlight.css"
      ],
      "js": [
        "js/jquery.js",
        "js/highlighter.js",
        "js/content-action.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b06d9d75-83d1-402b-a6e5-5b8c58ba6b93}"
    }
  }
}