Examine source code of RingCentral

{
  "manifest_version": 2,
  "version": "23.2.27",
  "name": "RingCentral for Firefox",
  "description": "RingCentral for Firefox",
  "permissions": [
    "http://*/",
    "https://*/",
    "storage",
    "activeTab",
    "tabs",
    "identity",
    "notifications",
    "unlimitedStorage",
    "https://*.google.com/*"
  ],
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "16": "assets/icon_16.png",
      "32": "assets/icon_32.png"
    }
  },
  "icons": {
    "16": "assets/icon_16.png",
    "32": "assets/icon_32.png",
    "48": "assets/icon_48.png",
    "128": "assets/icon_128.png"
  },
  "background": {
    "scripts": [
      "./config.js",
      "./background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "./config.js",
        "./content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "applications": {
    "gecko": {
      "id": "ringcentral-for-google-firefox@ringcentral.com",
      "strict_min_version": "65.0"
    }
  },
  "content_security_policy": "script-src 'self'; object-src 'self';"
}