Revert of Revert part of "Remove serializer-specific hash table size heuristic."

Revert of Revert part of "Remove serializer-specific hash table size heuristic." (patchset #1 id:1 of https://codereview.chromium.org/1272123002/ )

Reason for revert:
Did not fix issue it was intended to fix.

Original issue's description:
> Revert part of "Remove serializer-specific hash table size heuristic."
>
> TBR=machenbach@chromium.org
> NOTRY=true
> NOTREECHECKS=true
>
> Committed: https://crrev.com/68e5ae5282f3ba787c27ffa6e92fed6e5ff725e4
> Cr-Commit-Position: refs/heads/master@{#30021}

TBR=machenbach@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/d261c79064be3cfa5b706c2ee5793100e3c1ed52
Cr-Commit-Position: refs/heads/master@{#30022}

[Yang, 2015-08-05 10:26:46]

Created Revert of Revert part of "Remove serializer-specific hash table size
heuristic."

[commit-bot: I haz the power, 2015-08-05 10:26:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276443002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276443002/1

[commit-bot: I haz the power, 2015-08-05 10:28:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-05 10:28:15]

Patchset 1 (id:??) landed as
https://crrev.com/d261c79064be3cfa5b706c2ee5793100e3c1ed52
Cr-Commit-Position: refs/heads/master@{#30022}