Reland Shrink initial old generation size based on new space survival rate.

Reland Shrink initial old generation size based on new space survival rate.

I picked a more conservative start value this time of half max old generation size.

BUG=

Committed: https://crrev.com/e89318138c11a9fba3ffeaee103506ed5c1f84f6
Cr-Commit-Position: refs/heads/master@{#25890}

[Hannes Payer (out of office), 2014-12-18 15:54:37]

hpayer@chromium.org changed reviewers:
+ jochen@chromium.org

[jochen (gone - plz use gerrit), 2014-12-18 15:56:26]

lgtm

[Hannes Payer (out of office), 2014-12-18 16:27:57]

The CQ bit was checked by hpayer@chromium.org

[commit-bot: I haz the power, 2014-12-18 16:29:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/804323004/1

[commit-bot: I haz the power, 2014-12-18 16:55:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-12-18 18:05:45]

Patchset 1 (id:??) landed as
https://crrev.com/e89318138c11a9fba3ffeaee103506ed5c1f84f6
Cr-Commit-Position: refs/heads/master@{#25890}

[haraken, 2015-01-13 08:41:36]

On 2014/12/18 18:05:45, I haz the power (commit-bot) wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/e89318138c11a9fba3ffeaee103506ed5c1f84f6
> Cr-Commit-Position: refs/heads/master@{#25890}

Just FYI, this CL caused OOM in Dromaeo/dom-modify.html in Oilpan release
builds. The OOM happens only in oilpan builds, and I'm investigating why.