Reland of Check DisplayItemCient aliveness in cached subsequences

Reland of Check DisplayItemCient aliveness in cached subsequences (patchset #1 id:1 of https://codereview.chromium.org/2078393003/ )

Reason for revert:
It was not acceptable to revert the OwnPtr removal
patch just for this revert.

Relanding this to land OwnPtr commit again.

Original issue's description:
> Revert of Check DisplayItemCient aliveness in cached subsequences (patchset #6 id:100001 of https://codereview.chromium.org/2066603005/ )
>
> Reason for revert:
> Based on r400605 that is to be reverted.
>
> Original issue's description:
> > Check DisplayItemCient aliveness in cached subsequences
> >
> > BUG=609218
> >
> > Committed: https://crrev.com/127e5fadca5f431a5de1bef939f7f43aec1d136f
> > Cr-Commit-Position: refs/heads/master@{#400607}
>
> TBR=chrishtr@chromium.org,wangxianzhu@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=609218
>
> Committed: https://chromium.googlesource.com/chromium/src/+/6ece4aaeb5e2c53eca2617d42de64ff917cee884

TBR=chrishtr@chromium.org,wangxianzhu@chromium.org,vasilii@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=609218
Committed: https://crrev.com/669d0139a244c04dc7c2834b3d0a928e0b5a7bde
Cr-Commit-Position: refs/heads/master@{#400645}

[Yuta Kitamura, 2016-06-20 10:50:50]

The CQ bit was checked by yutak@chromium.org

[Yuta Kitamura, 2016-06-20 10:50:51]

Created Reland of Check DisplayItemCient aliveness in cached subsequences

[commit-bot: I haz the power, 2016-06-20 10:51:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2082553002/1

[commit-bot: I haz the power, 2016-06-20 10:53:09]

Description was changed from

==========
Reland of Check DisplayItemCient aliveness in cached subsequences (patchset #1
id:1 of https://codereview.chromium.org/2078393003/ )

Reason for revert:
It was not acceptable to revert the OwnPtr removal
patch just for this revert.

Relanding this to land OwnPtr commit again.

Original issue's description:
> Revert of Check DisplayItemCient aliveness in cached subsequences (patchset #6
id:100001 of https://codereview.chromium.org/2066603005/ )
> 
> Reason for revert:
> Based on r400605 that is to be reverted.
> 
> Original issue's description:
> > Check DisplayItemCient aliveness in cached subsequences
> > 
> > BUG=609218
> > 
> > Committed: https://crrev.com/127e5fadca5f431a5de1bef939f7f43aec1d136f
> > Cr-Commit-Position: refs/heads/master@{#400607}
> 
> TBR=chrishtr@chromium.org,wangxianzhu@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=609218
> 
> Committed:
https://chromium.googlesource.com/chromium/src/+/6ece4aaeb5e2c53eca2617d42de6...

TBR=chrishtr@chromium.org,wangxianzhu@chromium.org,vasilii@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=609218
==========

to

==========
Reland of Check DisplayItemCient aliveness in cached subsequences (patchset #1
id:1 of https://codereview.chromium.org/2078393003/ )

Reason for revert:
It was not acceptable to revert the OwnPtr removal
patch just for this revert.

Relanding this to land OwnPtr commit again.

Original issue's description:
> Revert of Check DisplayItemCient aliveness in cached subsequences (patchset #6
id:100001 of https://codereview.chromium.org/2066603005/ )
> 
> Reason for revert:
> Based on r400605 that is to be reverted.
> 
> Original issue's description:
> > Check DisplayItemCient aliveness in cached subsequences
> > 
> > BUG=609218
> > 
> > Committed: https://crrev.com/127e5fadca5f431a5de1bef939f7f43aec1d136f
> > Cr-Commit-Position: refs/heads/master@{#400607}
> 
> TBR=chrishtr@chromium.org,wangxianzhu@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=609218
> 
> Committed:
https://chromium.googlesource.com/chromium/src/+/6ece4aaeb5e2c53eca2617d42de6...

TBR=chrishtr@chromium.org,wangxianzhu@chromium.org,vasilii@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=609218
==========

[commit-bot: I haz the power, 2016-06-20 10:53:10]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-20 10:54:57]

Description was changed from

==========
Reland of Check DisplayItemCient aliveness in cached subsequences (patchset #1
id:1 of https://codereview.chromium.org/2078393003/ )

Reason for revert:
It was not acceptable to revert the OwnPtr removal
patch just for this revert.

Relanding this to land OwnPtr commit again.

Original issue's description:
> Revert of Check DisplayItemCient aliveness in cached subsequences (patchset #6
id:100001 of https://codereview.chromium.org/2066603005/ )
> 
> Reason for revert:
> Based on r400605 that is to be reverted.
> 
> Original issue's description:
> > Check DisplayItemCient aliveness in cached subsequences
> > 
> > BUG=609218
> > 
> > Committed: https://crrev.com/127e5fadca5f431a5de1bef939f7f43aec1d136f
> > Cr-Commit-Position: refs/heads/master@{#400607}
> 
> TBR=chrishtr@chromium.org,wangxianzhu@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=609218
> 
> Committed:
https://chromium.googlesource.com/chromium/src/+/6ece4aaeb5e2c53eca2617d42de6...

TBR=chrishtr@chromium.org,wangxianzhu@chromium.org,vasilii@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=609218
==========

to

==========
Reland of Check DisplayItemCient aliveness in cached subsequences (patchset #1
id:1 of https://codereview.chromium.org/2078393003/ )

Reason for revert:
It was not acceptable to revert the OwnPtr removal
patch just for this revert.

Relanding this to land OwnPtr commit again.

Original issue's description:
> Revert of Check DisplayItemCient aliveness in cached subsequences (patchset #6
id:100001 of https://codereview.chromium.org/2066603005/ )
>
> Reason for revert:
> Based on r400605 that is to be reverted.
>
> Original issue's description:
> > Check DisplayItemCient aliveness in cached subsequences
> >
> > BUG=609218
> >
> > Committed: https://crrev.com/127e5fadca5f431a5de1bef939f7f43aec1d136f
> > Cr-Commit-Position: refs/heads/master@{#400607}
>
> TBR=chrishtr@chromium.org,wangxianzhu@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=609218
>
> Committed:
https://chromium.googlesource.com/chromium/src/+/6ece4aaeb5e2c53eca2617d42de6...

TBR=chrishtr@chromium.org,wangxianzhu@chromium.org,vasilii@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=609218

Committed: https://crrev.com/669d0139a244c04dc7c2834b3d0a928e0b5a7bde
Cr-Commit-Position: refs/heads/master@{#400645}
==========

[commit-bot: I haz the power, 2016-06-20 10:54:59]

Patchset 1 (id:??) landed as
https://crrev.com/669d0139a244c04dc7c2834b3d0a928e0b5a7bde
Cr-Commit-Position: refs/heads/master@{#400645}