Reland of [heap] Cleanup mark bit usage.

Reland of [heap] Cleanup mark bit usage. (patchset #1 id:1 of https://codereview.chromium.org/1490753003/ )

Reason for revert:
Reland after fixing the potential root cause of the canary crasher.

Original issue's description:
> Revert of [heap] Cleanup mark bit usage. (patchset #1 id:1 of https://codereview.chromium.org/1474203003/ )
>
> Reason for revert:
> Still investigating bad canary.
>
> Original issue's description:
> > [heap] Cleanup mark bit usage.
> >
> > BUG=
> >
> > Committed: https://crrev.com/5874ac783ff9bc4bb4b2fda81f5077f06619f96c
> > Cr-Commit-Position: refs/heads/master@{#32362}
>
> TBR=mlippautz@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=
>
> Committed: https://crrev.com/d3faef8658598e68331208b5a1846ac1c250cb49
> Cr-Commit-Position: refs/heads/master@{#32461}

TBR=mlippautz@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: https://crrev.com/0240d202651c89a93fdf2b50bf06bedb4e603b9a
Cr-Commit-Position: refs/heads/master@{#32502}

[Hannes Payer (out of office), 2015-12-02 11:03:22]

Created Reland of [heap] Cleanup mark bit usage.

[commit-bot: I haz the power, 2015-12-02 11:03:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1488393003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1488393003/1

[commit-bot: I haz the power, 2015-12-02 11:05:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-02 11:06:03]

Description was changed from

==========
Reland of [heap] Cleanup mark bit usage. (patchset #1 id:1 of
https://codereview.chromium.org/1490753003/ )

Reason for revert:
Reland after fixing the potential root cause of the canary crasher.

Original issue's description:
> Revert of [heap] Cleanup mark bit usage. (patchset #1 id:1 of
https://codereview.chromium.org/1474203003/ )
> 
> Reason for revert:
> Still investigating bad canary.
> 
> Original issue's description:
> > [heap] Cleanup mark bit usage.
> >
> > BUG=
> >
> > Committed: https://crrev.com/5874ac783ff9bc4bb4b2fda81f5077f06619f96c
> > Cr-Commit-Position: refs/heads/master@{#32362}
> 
> TBR=mlippautz@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=
> 
> Committed: https://crrev.com/d3faef8658598e68331208b5a1846ac1c250cb49
> Cr-Commit-Position: refs/heads/master@{#32461}

TBR=mlippautz@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
==========

to

==========
Reland of [heap] Cleanup mark bit usage. (patchset #1 id:1 of
https://codereview.chromium.org/1490753003/ )

Reason for revert:
Reland after fixing the potential root cause of the canary crasher.

Original issue's description:
> Revert of [heap] Cleanup mark bit usage. (patchset #1 id:1 of
https://codereview.chromium.org/1474203003/ )
>
> Reason for revert:
> Still investigating bad canary.
>
> Original issue's description:
> > [heap] Cleanup mark bit usage.
> >
> > BUG=
> >
> > Committed: https://crrev.com/5874ac783ff9bc4bb4b2fda81f5077f06619f96c
> > Cr-Commit-Position: refs/heads/master@{#32362}
>
> TBR=mlippautz@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=
>
> Committed: https://crrev.com/d3faef8658598e68331208b5a1846ac1c250cb49
> Cr-Commit-Position: refs/heads/master@{#32461}

TBR=mlippautz@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: https://crrev.com/0240d202651c89a93fdf2b50bf06bedb4e603b9a
Cr-Commit-Position: refs/heads/master@{#32502}
==========

[commit-bot: I haz the power, 2015-12-02 11:06:04]

Patchset 1 (id:??) landed as
https://crrev.com/0240d202651c89a93fdf2b50bf06bedb4e603b9a
Cr-Commit-Position: refs/heads/master@{#32502}