7 files declare their use of Bytes in Zircon Profile 8

BytesTest.php in core/tests/Drupal/Tests/Component/Utility/BytesTest.php

Contains \Drupal\Tests\Component\Utility\BytesTest.

color.module in core/modules/color/color.module

Allows users to change the color scheme of themes.

common.inc in core/includes/common.inc

Common functions that many Drupal modules will need to reference.

EditorImageDialog.php in core/modules/editor/src/Form/EditorImageDialog.php

Contains \Drupal\editor\Form\EditorImageDialog.

file.inc in core/includes/file.inc

API for handling file uploads and server file management.

FileItem.php in core/modules/file/src/Plugin/Field/FieldType/FileItem.php

Contains \Drupal\file\Plugin\Field\FieldType\FileItem.

SizeUnitTest.php in core/modules/system/src/Tests/Common/SizeUnitTest.php

Contains \Drupal\system\Tests\Common\SizeUnitTest.