Revert of Move postGC out of CrossThreadPersistentRegion::LockScope

Revert of Move postGC out of CrossThreadPersistentRegion::LockScope (patchset #2 id:20001 of https://codereview.chromium.org/2695063005/ )

Reason for revert:
Broke build.
crbug.com/692982

Original issue's description:
> Move postGC out of CrossThreadPersistentRegion::LockScope
> 
> Some finalizers/prefinalizers acquire locks, causing a dead lock when CrossThreadPersistent tries to acquire the CrossThreadPersistentRegion lock.
> 
> This CL moves the postGC step outside of the CrossThreadPersistentRegion::LockScope. This should be okay as the CrossThreadPersistentRegion::LockScope only exists to avoid add/deletetion of CrossThreadPersistentNodes during marking.
> 
> BUG=681527, 684856, 685624, 685624
> 
> Review-Url: https://codereview.chromium.org/2686533003
> Cr-Commit-Position: refs/heads/master@{#450251}
> (cherry picked from commit 52b19c8f68c222c08944af937a01f3ff7e46705c)
> 
> Review-Url: https://codereview.chromium.org/2695063005 .
> Cr-Commit-Position: refs/branch-heads/2987@{#539}
> Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
> Committed: https://chromium.googlesource.com/chromium/src/+/590a7c6ceb9bea92bbce8e7636406ed6ea39bfe8

TBR=
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=681527, 684856, 685624, 685624
Review-Url: https://codereview.chromium.org/2701513003
Cr-Commit-Position: refs/branch-heads/2987@{#541}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed: https://chromium.googlesource.com/chromium/src/+/3d80b9d4de29bc69458e1c27eb8bce181d7dcb27

[keishi, 2017-02-16 09:26:26]

The CQ bit was checked by keishi@chromium.org

[keishi, 2017-02-16 09:26:26]

Created Revert of Move postGC out of CrossThreadPersistentRegion::LockScope

[commit-bot: I haz the power, 2017-02-16 09:27:07]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-02-16 09:29:23]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1487237186194570, "parent_rev":
"590a7c6ceb9bea92bbce8e7636406ed6ea39bfe8", "commit_rev":
"96f491d7e7f99d7ee4f448800ee94df7c0a99a13"}

[commit-bot: I haz the power, 2017-02-16 09:33:17]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-02-16 09:33:27]

Prior attempt to commit was detected, but we were not able to check whether the
issue was successfully committed. Please check Git history manually and re-check
CQ or close this issue as needed.

[keishi, 2017-02-16 09:48:26]

The CQ bit was checked by keishi@chromium.org

[commit-bot: I haz the power, 2017-02-16 09:49:10]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-02-16 09:50:51]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1487238506051380, "parent_rev":
"7ca30d63ded3525cdab87cb205161ba3751b75ab", "commit_rev":
"3d80b9d4de29bc69458e1c27eb8bce181d7dcb27"}

[commit-bot: I haz the power, 2017-02-16 09:51:41]

Description was changed from

==========
Revert of Move postGC out of CrossThreadPersistentRegion::LockScope (patchset #2
id:20001 of https://codereview.chromium.org/2695063005/ )

Reason for revert:
Broke build.
crbug.com/692982

Original issue's description:
> Move postGC out of CrossThreadPersistentRegion::LockScope
> 
> Some finalizers/prefinalizers acquire locks, causing a dead lock when
CrossThreadPersistent tries to acquire the CrossThreadPersistentRegion lock.
> 
> This CL moves the postGC step outside of the
CrossThreadPersistentRegion::LockScope. This should be okay as the
CrossThreadPersistentRegion::LockScope only exists to avoid add/deletetion of
CrossThreadPersistentNodes during marking.
> 
> BUG=681527,684856,685624,685624
> 
> Review-Url: https://codereview.chromium.org/2686533003
> Cr-Commit-Position: refs/heads/master@{#450251}
> (cherry picked from commit 52b19c8f68c222c08944af937a01f3ff7e46705c)
> 
> Review-Url: https://codereview.chromium.org/2695063005 .
> Cr-Commit-Position: refs/branch-heads/2987@{#539}
> Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
> Committed:
https://chromium.googlesource.com/chromium/src/+/590a7c6ceb9bea92bbce8e763640...

TBR=
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=681527,684856,685624,685624
==========

to

==========
Revert of Move postGC out of CrossThreadPersistentRegion::LockScope (patchset #2
id:20001 of https://codereview.chromium.org/2695063005/ )

Reason for revert:
Broke build.
crbug.com/692982

Original issue's description:
> Move postGC out of CrossThreadPersistentRegion::LockScope
> 
> Some finalizers/prefinalizers acquire locks, causing a dead lock when
CrossThreadPersistent tries to acquire the CrossThreadPersistentRegion lock.
> 
> This CL moves the postGC step outside of the
CrossThreadPersistentRegion::LockScope. This should be okay as the
CrossThreadPersistentRegion::LockScope only exists to avoid add/deletetion of
CrossThreadPersistentNodes during marking.
> 
> BUG=681527,684856,685624,685624
> 
> Review-Url: https://codereview.chromium.org/2686533003
> Cr-Commit-Position: refs/heads/master@{#450251}
> (cherry picked from commit 52b19c8f68c222c08944af937a01f3ff7e46705c)
> 
> Review-Url: https://codereview.chromium.org/2695063005 .
> Cr-Commit-Position: refs/branch-heads/2987@{#539}
> Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
> Committed:
https://chromium.googlesource.com/chromium/src/+/590a7c6ceb9bea92bbce8e763640...

TBR=
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=681527,684856,685624,685624

Review-Url: https://codereview.chromium.org/2701513003
Cr-Commit-Position: refs/branch-heads/2987@{#541}
Cr-Branched-From:
ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}
Committed:
https://chromium.googlesource.com/chromium/src/+/3d80b9d4de29bc69458e1c27eb8b...
==========

[commit-bot: I haz the power, 2017-02-16 09:51:42]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/3d80b9d4de29bc69458e1c27eb8b...