[heap] Fix Unmapper::TearDown to include delayed chunks

[heap] Fix Unmapper::TearDown to include delayed chunks

Delayed chunks in the unmapper are chunks that should be unmapped but could
potentially still be accessed by the sweeper (page header), hence their
unmapping is delayed.

During TearDown, however, we need to properly unmap those pages, i.e., check
that they can now be unmapped (should always hold) and properly unmap them.

BUG=chromium:656537
R=ulan@chromium.org

Committed: https://crrev.com/588641f242f4adf5240ca02d95c945afa40ab6c9
Cr-Commit-Position: refs/heads/master@{#40698}

[ulan, 2016-11-02 12:26:29]

lgtm

[Michael Lippautz, 2016-11-02 12:39:14]

The CQ bit was checked by mlippautz@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-02 12:39:16]

Dry run: 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, 2016-11-02 13:05:08]

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

[commit-bot: I haz the power, 2016-11-02 13:05:09]

Dry run: This issue passed the CQ dry run.

[Michael Lippautz, 2016-11-02 13:08:22]

The CQ bit was checked by mlippautz@chromium.org

[commit-bot: I haz the power, 2016-11-02 13:08:26]

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, 2016-11-02 13:10:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-17 22:19:15]

Description was changed from

==========
[heap] Fix Unmapper::TearDown to include delayed chunks

Delayed chunks in the unmapper are chunks that should be unmapped but could
potentially still be accessed by the sweeper (page header), hence their
unmapping is delayed.

During TearDown, however, we need to properly unmap those pages, i.e., check
that they can now be unmapped (should always hold) and properly unmap them.

BUG=chromium:656537
R=ulan@chromium.org
==========

to

==========
[heap] Fix Unmapper::TearDown to include delayed chunks

Delayed chunks in the unmapper are chunks that should be unmapped but could
potentially still be accessed by the sweeper (page header), hence their
unmapping is delayed.

During TearDown, however, we need to properly unmap those pages, i.e., check
that they can now be unmapped (should always hold) and properly unmap them.

BUG=chromium:656537
R=ulan@chromium.org

Committed: https://crrev.com/588641f242f4adf5240ca02d95c945afa40ab6c9
Cr-Commit-Position: refs/heads/master@{#40698}
==========

[commit-bot: I haz the power, 2016-11-17 22:19:16]

Patchset 1 (id:??) landed as
https://crrev.com/588641f242f4adf5240ca02d95c945afa40ab6c9
Cr-Commit-Position: refs/heads/master@{#40698}