Examine source code of Hangouts RTL fixer

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Hangouts RTL fixer",
  "description": "This extension fixes the text direction in Google Hangouts (Gmail chat) for RTL languages",
  "version": "1.0.2",
  "author": "zvizvi5@outlook.com",
  "permissions": [
    "https://hangouts.google.com/webchat/*"
  ],
  "icons": {
    "48": "images/icon_48.png",
    "128": "images/icon_128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon_16.png",
      "22": "images/icon_22.png",
      "24": "images/icon_24.png",
      "32": "images/icon_32.png",
      "44": "images/icon_44.png"
    }
  },
  "content_scripts": [
    {
      "js": [
        "js/main.js"
      ],
      "matches": [
        "https://hangouts.google.com/webchat/*"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ]
}