Revert "Reland "Add Abseil to third_party.""

This reverts commit 78debd6f6d833b8eb0896931b904b83b8bd6b737.

Reason for revert: unexpectedly, Test-Mac10.13-Clang-MacBookPro11.5-CPU-AVX2-x86_64-Release-All-TSAN

Original change's description:
> Reland "Add Abseil to third_party."
>
> This is a reland of 816226e822635011c4e9dae6fb1d5ed8113bfbfd
>
> Original change's description:
> > Add Abseil to third_party.
> >
> > At present, this is a proof-of-concept which only supports a small
> > subset of absl modules:
> > - Base
> > - Hash
> > - Numeric
> > - String
> >
> > This is only used by one unit test, which builds a string and then
> > hashes it.
> >
> > Bug: skia:10165
> > Bug: b/154848688
> >
> > Change-Id: I016250bf700b522c7a6bc78cf1844abff2260c35
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/284805
> > Reviewed-by: Derek Sollenberger <djsollen@google.com>
> > Commit-Queue: John Stiles <johnstiles@google.com>
> > Auto-Submit: John Stiles <johnstiles@google.com>
>
> Bug: skia:10165, b/154848688
> Change-Id: I618bb4411445fe5b45a91741934ca888a09adf05
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285537
> Commit-Queue: John Stiles <johnstiles@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>

TBR=djsollen@google.com,mtklein@google.com,johnstiles@google.com

Change-Id: I434da738bcc7fa76b46d0fa0fcbdd58c85b70fe7
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:10165, skia:10177, b/154848688
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285685
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
5 files changed