Since only standard appearance keywords should be supported, we are removing the appearance (and -webkit-appearance) keywords that shouldn't be supported anymore: * inner-spin-button * media-slider * media-sliderthumb * media-volume-slider * media-volume-sliderthumb * push-button * searchfield-cancel-button * slider-horizontal * sliderthumb-horizontal * sliderthumb-vertical * square-button Note that value "slider-vertical" will not be removed as part of this patch it is used for allowing <input type=range> vertical. It will be removed once feature FormControlsVerticalWritingModeSupport is enabled in stable. With the feature enabled, if using any of the above keywords, a console warning will be shown, but the keyword will be recognized as a valid value. With the feature disabled, the appearance property will be ignored. As needed for Web compatibility, we will progressively remove the appearance keywords based on their usage: * --disable-features=NonStandardAppearanceValuesLowUsage * --disable-features=NonStandardAppearanceValuesHighUsage For release 118, we will disable the low usage values, currently at page load usage below 0.001%. * media-slider at 0.000361 * media-sliderthumb at 0.000187% * media-volume-slider at 0.000143% * media-volume-sliderthumb at 0.000109% * sliderthumb-horizontal at 0.000182% * sliderthumb-vertical at 0.000014%
We should remove non-standard -webkit-appearance keywords and only support the keywords listed in the standards.