[Oilpan] Replace a raw pointer to RawPtrWillBeMember to estimate size

Replace a raw pointer to RawPtrWillBeMember to estimate size explicitly.

This is a follow-up CL of https://crrev.com/7818e07434df5da87d6cdfe0d30830bf2191097e .

BUG=550325
Committed: https://crrev.com/a91f4345158a5cd33931325312703a4e294512d0
Cr-Commit-Position: refs/heads/master@{#359049}

[peria, 2015-11-11 02:00:10]

Description was changed from

==========
Replace a raw pointer to RawPtrWillBeMember to estimate size

BUG=
==========

to

==========
Replace a raw pointer to RawPtrWillBeMember to estimate size explicitly.

This is a follow-up CL of
https://crrev.com/7818e07434df5da87d6cdfe0d30830bf2191097e .


BUG=550325
==========

[peria, 2015-11-11 02:00:45]

peria@chromium.org changed reviewers:
+ haraken@chromium.org, oilpan-reviews@chromium.org

[peria, 2015-11-11 02:00:45]

PTL

[haraken, 2015-11-11 03:06:27]

LGTM

[peria, 2015-11-11 03:06:57]

The CQ bit was checked by peria@chromium.org

[commit-bot: I haz the power, 2015-11-11 03:07:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1433843002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1433843002/1

[commit-bot: I haz the power, 2015-11-11 04:17:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-11 04:18:28]

Patchset 1 (id:??) landed as
https://crrev.com/a91f4345158a5cd33931325312703a4e294512d0
Cr-Commit-Position: refs/heads/master@{#359049}