chromium/third_party/blink/web_tests/virtual/slider-vertical-enabled/README.md

# This suite runs tests with --enabled-blink-features=NonStandardAppearanceValueSliderVertical.

This test suite is to make sure that, when the feature is enabled, users are seeing the deprecation warnings correctly and the non-standard CSS appearance value slider-vertical will influence rendering.
This test can be removed when the feature is shipped.