Avoid excessive GCs in small heaps.

Avoid excessive GCs in small heaps.

Small heaps and small heap growing factor can lead to excessive GCs in corner cases.

Consider function F(old_gen_size, factor) that returns the number of bytes that
have to be allocated in the old generation to start incremental marking.

F(4MB, 1.1) = 4MB (because of kMinimumOldGenerationAllocationLimit)
F(6MB, 1.1) = 2MB (because of kMinimumOldGenerationAllocationLimit)
F(8MB, 1.1) = 800KB

Funtion F should be monotonic in old_gen_size, but it currently has a minimum
at kMinimumOldGenerationAllocationLimit.

This CL makes F monotonic.

BUG=

Committed: https://crrev.com/22b1da99732b4db0754bf267ec470a2831216fb2
Cr-Commit-Position: refs/heads/master@{#28549}

[ulan, 2015-05-20 17:48:51]

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

[ulan, 2015-05-20 17:48:52]

PTAL

[Hannes Payer (out of office), 2015-05-21 12:21:25]

lgtm

[ulan, 2015-05-21 12:23:53]

The CQ bit was checked by ulan@chromium.org

[commit-bot: I haz the power, 2015-05-21 12:23:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1144223002/1

[commit-bot: I haz the power, 2015-05-21 12:50:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-21 12:51:06]

Patchset 1 (id:??) landed as
https://crrev.com/22b1da99732b4db0754bf267ec470a2831216fb2
Cr-Commit-Position: refs/heads/master@{#28549}

[ulan, 2015-05-21 14:46:54]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1152533002/ by ulan@chromium.org.

The reason for reverting is: Regressed Sunspider..