Use for-of loops in collection constructors

Use for-of loops in collection constructors

This is to reduce code duplication but also to get the correct
behavior when we make for-of handle abrupt completion correctly.

BUG=None
LOG=N
R=adamk

Committed: https://crrev.com/8ad35cb288498129a557bf7c80886126fa9a7904
Cr-Commit-Position: refs/heads/master@{#26834}

[arv (Not doing code reviews), 2015-02-24 17:53:54]

PTAL

[adamk, 2015-02-24 18:44:49]

No test changes? I thought the change you landed yesterday already changed
for-of behavior.

[arv (Not doing code reviews), 2015-02-24 18:45:58]

On 2015/02/24 18:44:49, adamk wrote:
> No test changes? I thought the change you landed yesterday already changed
> for-of behavior.

No change in behavior. The old manual loop already handled the case where the
result object was not an object.

[adamk, 2015-02-24 18:47:09]

lgtm

[arv (Not doing code reviews), 2015-02-24 18:51:42]

The CQ bit was checked by arv@chromium.org

[commit-bot: I haz the power, 2015-02-24 18:52:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/956623003/1

[commit-bot: I haz the power, 2015-02-24 19:12:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-24 19:12:52]

Patchset 1 (id:??) landed as
https://crrev.com/8ad35cb288498129a557bf7c80886126fa9a7904
Cr-Commit-Position: refs/heads/master@{#26834}