Examine source code of Protect message

{
  "name": "Protect message",
  "short_name": "bMessage",
  "version": "2.0.1",
  "description": "This extension allow users to prevent peeking messages on Messenger and Facebook by blurring or reverse mirror effect.",
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "16": "icons/16.png",
      "24": "icons/24.png",
      "32": "icons/32.png",
      "48": "icons/48.png",
      "128": "icons/128.png"
    },
    "default_title": "Protect message setting",
    "default_popup": "src/popup.html"
  },
  "author": "https://www.facebook.com/hafquangbaox",
  "homepage_url": "https://github.com/lozthiensu/bMessenger",
  "icons": {
    "16": "icons/16.png",
    "24": "icons/24.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.fb.com/*",
        "*://*.facebook.com/*",
        "*://*.m.me/*",
        "*://*.messenger.com/*"
      ],
      "js": [
        "src/content.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "tabs",
    "contextMenus",
    "*://*.fb.com/*",
    "*://*.facebook.com/*",
    "*://*.m.me/*",
    "*://*.messenger.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "quanngbao1994@gmail.com",
      "strict_min_version": "42.0"
    }
  }
}