Blink supports auto in CSSParserFastPaths::IsValidKeywordPropertyAndValue and StyleBuilderFunctions::applyValueCSSPropertyResize
but not in CSSProperties.json5 / generated cssom_keywords.cc

We should add a use counter for resize auto; perhaps count in StyleBuilderFunctions::applyValueCSSPropertyResize.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/df9cd6509a0b5bb508907055729823f58a67a618

commit df9cd6509a0b5bb508907055729823f58a67a618
Author: Hwanseung Lee <hs1217.lee@samsung.com>
Date: Thu Apr 12 13:08:55 2018

add use counter for resize with auto value

recent versions of the spec do not support 'auto' value.
so before retire that value, we should check how many use it.

Bug: 831550
Change-Id: I3b551ea759d05cade1e8823f3dc1c68f30b65816
Reviewed-on: https://chromium-review.googlesource.com/1007294
Commit-Queue: Hwanseung Lee <hwanseung@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Eric Willigers <ericwilligers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550166}
[modify] https://crrev.com/df9cd6509a0b5bb508907055729823f58a67a618/third_party/blink/public/platform/web_feature.mojom
[modify] https://crrev.com/df9cd6509a0b5bb508907055729823f58a67a618/third_party/blink/renderer/core/css/resolver/style_builder_custom.cc
[modify] https://crrev.com/df9cd6509a0b5bb508907055729823f58a67a618/tools/metrics/histograms/enums.xml

https://www.chromestatus.com/metrics/feature/timeline/popularity/2418
this is page which is stats of usage.

Shows around 25%?

I guess this is WontFix.

> Blink, Edge, WebKit still support auto; Firefox does not.

Update or correction:
Only Blink and WebKit support 'auto', not Edge or Firefox.
https://wpt.fyi/results/css/css-ui/parsing/resize-invalid.html