This reverts commit 9072bef0.

Reason for revert: Speculative revert because of https://chromium-review.googlesource.com/c/chromium/src/+/1118280

Original change's description:
> Reland "[heap] Added per-page array buffer accouting (external memory)."
> 
> This is a reland of d4792e8f
> 
> Original change's description:
> > [heap] Added per-page array buffer accouting (external memory).
> > 
> > Bug: chromium:845409
> > Change-Id: Ibc568cdc501edf5d84d9c6379aff58be069369af
> > Reviewed-on: https://chromium-review.googlesource.com/1114602
> > Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#54028}
> 
> Bug: chromium:845409
> Change-Id: I6b11d7f66313bcbcc31be9217c1b780cf3eaee99
> Reviewed-on: https://chromium-review.googlesource.com/1116638
> Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#54066}

TBR=ulan@chromium.org,hpayer@chromium.org,mlippautz@chromium.org,rfbpb@google.com

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

Bug: chromium:845409
Change-Id: I818e24d236d93a4645d1532b666056f89156eb86
Reviewed-on: https://chromium-review.googlesource.com/1119825Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Michael Hablich <hablich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54100}