chromium/ios/web/public/permissions/README.md

This directory contains three enums:
  - Permission specifies different data or device hardwares that the app/site needs access permissions to; currently we have camera and microphone.
  - PermissionState specifies whether the user has granted the site permission to use a certain type of permission.
  - PermissionDecision an enumeration based on `WKPermissionDecision` to specifies the possible permission decisions for device resource access