Bug 1580395 [wpt PR 18981] - Revert "Switch InterpolableLength implementation from...

Bug 1580395 [wpt PR 18981] - Revert "Switch InterpolableLength implementation from length array to expression", a=testonly

Automatic update from web-platform-tests
Revert "Switch InterpolableLength implementation from length array to expression"

This reverts commit dd1318d7b1537af982313d51433e00fc02421225.

Reason for revert: caused performance regression crbug.com/1002177

Original change's description:
> Switch InterpolableLength implementation from length array to expression
>
> This patch changes the internal implementation of InterpolableLength
> from CSSLengthArray to the following:
> - A CSSNumericLiteralValue to keep it simple when it's a simple value
> - A CSSMathExpressionNode to make it general when the underlying length
>   involves calculation and math functions
>
> In this way, we can interpolate when the length cannot be represented
> as a CSSLengthArray (i.e., when comparison functions min/max are
> involved).
>
> Bug: 991672
> Change-Id: Ib83fc0a07d0eb1d03a2465ac9df5282f963b935b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1777025
> Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
> Reviewed-by: Alan Cutter <alancutter@chromium.org>
> Reviewed-by: Emil A Eklund <eae@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#694443}

TBR=alancutter@chromium.org,eae@chromium.org,xiaochengh@chromium.org,futhark@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 991672
Change-Id: I4467c0b4c8202dbc38ac5152620666caa38648e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1797822
Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695498}

--

wpt-commits: f69dc54a5a51458aa664657768feba456d1ef6f4
wpt-pr: 18981