Immediately "optimize as prototype" when setting as prototype of a function.

Immediately "optimize as prototype" when setting as prototype of a function.

This saves space since OptimizeAsPrototype detaches from the transition tree, reclaiming intermediate maps. On gmail this corresponds to roughly 20% of all maps.

BUG=

Committed: https://crrev.com/fade797d02a2c3da305004803eccc45ea9b103e2
Cr-Commit-Position: refs/heads/master@{#26772}

[Toon Verwaest, 2015-02-20 10:34:36]

verwaest@chromium.org changed reviewers:
+ ishell@chromium.org

[Toon Verwaest, 2015-02-20 10:34:36]

PTAL

[Igor Sheludko, 2015-02-20 11:12:27]

lgtm

[Toon Verwaest, 2015-02-20 11:52:28]

New patchsets have been uploaded after l-g-t-m from ishell@chromium.org

[Toon Verwaest, 2015-02-20 11:52:56]

The CQ bit was checked by verwaest@chromium.org

[commit-bot: I haz the power, 2015-02-20 11:53:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/941213005/40001

[commit-bot: I haz the power, 2015-02-20 12:24:01]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-20 12:24:29]

Patchset 3 (id:??) landed as
https://crrev.com/fade797d02a2c3da305004803eccc45ea9b103e2
Cr-Commit-Position: refs/heads/master@{#26772}