Add CSSValueAppearanceSearchCancelForOthers2Rendered UseCounter.

CSSValueAppearanceSearchCancelForOthersRendered unexpectedly includes
-webkit-appearance:searchfield-cancel-button usage with shadow element
representing clear button in
input[type=date/datetime-local/month/time/week]. This CL adds a fixed
counter, and keep the wrong one just in case.

Bug: 892586
Change-Id: Icebc3057605c0f31131e822df997e929c8855c27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1626916
Commit-Queue: Kent Tamura <tkent@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663454}