Reland of Ensure counters are initialized, to avoid init on non-joinable threads. (patchset #1 id:1 of https://codereview.chromium.org/2812653002/ )

Reason for revert:
Appears to be a flake. Both jgruber and I tried to repro locally and failed. Also change has little change of having had caused those failures.

Original issue's description:
> Revert of Ensure counters are initialized, to avoid init on non-joinable threads. (patchset #1 id:1 of https://codereview.chromium.org/2812543002/ )
>
> Reason for revert:
> https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20gyp/builds/5221
>
> Original issue's description:
> > Ensure counters are initialized, to avoid init on non-joinable threads.
> >
> > This occurs in the wasm scenario described in the referenced bug.
> > DecodeWasmModule collects statistics. Blink inserts a CreateHistogramCallback that
> > can't instantiate a histogram on non-joinable threads. Turns out, DecodeWasmModule
> > is scheduled on such a thread, now that we have async compilation.
> >
> > This fix pre-initializes histograms when the callback is applied, which is assumed to
> > be in a context that can carry out the instantiation. In Blink, this happens on the main
> > thread.
> >
> > BUG=chromium:709684
> >
> > Review-Url: https://codereview.chromium.org/2812543002
> > Cr-Commit-Position: refs/heads/master@{#44522}
> > Committed: https://chromium.googlesource.com/v8/v8/+/022e7ddf232b0696eb595769fa702463c417db5e
>
> TBR=jochen@chromium.org,mtrofin@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:709684
>
> Review-Url: https://codereview.chromium.org/2812653002
> Cr-Commit-Position: refs/heads/master@{#44527}
> Committed: https://chromium.googlesource.com/v8/v8/+/038bafcb8c0435bc4130228237124331295d4713

TBR=jochen@chromium.org,jgruber@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:709684

Review-Url: https://codereview.chromium.org/2813673002
Cr-Commit-Position: refs/heads/master@{#44529}