Examine source code of Twitch Cleanser 3000

{
  "manifest_version": 2,
  "name": "Twitch Cleanser 3000",
  "version": "1.0",
  "description": "Say goodbye to spam and hello to pristine chatrooms with Twitch Cleanser 3000! This Mozilla Firefox extension remembers messages for a whole hour and vaporizes repeated messages faster than you can say PogChomp. Get ready to be the hero your chat deserves, and clean up your Twitch chat with Twitch Cleanser 3000 today!",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.twitch.tv/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{060da203-b9b2-4149-81b7-036b11cdc933}"
    }
  }
}