Revert "[LayoutNG] Heap allocate algorithms to save stack space."

This reverts commit ba345fef12ea7eab8b5637d17390e7749ec31ac6.

Reason for revert: Now that win32 stack has increased to 1.5MB[1] we
can reclaim perf. and revert this change.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1682227

Original change's description:
> [LayoutNG] Heap allocate algorithms to save stack space.
> 
> This moves NGLayoutAlgorithm onto the heap using partition alloc.
> 
> This (in mac-64bit) reduces the stack space from 1392 -> 864 bytes
> which is the same as legacy.
> 
> From pinpoint data, this only seems to have a slight performance
> regression.
> 
> A follow up patch will be sent so which performs a refactoring, so that
> this patch can be a simple cherry pick with the beta branch.
> 
> Bug: 977387
> Change-Id: I75a5b995b26c60e69976f41876cea192bc761486
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1669917
> Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
> Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
> Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#672086}

TBR=cbiesinger@chromium.org,ikilpatrick@chromium.org,mstensho@chromium.org

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

Bug: 977387
Change-Id: I694977bee640df021f79f0926e5da723d6f2b911
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1692239
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675732}