Use LookupIterator for elements in the observed part of DefineAccessor

Use LookupIterator for elements in the observed part of DefineAccessor

BUG=v8:4137
LOG=n

Committed: https://crrev.com/83abd09597039c7122e1aab1bfa8851cf0c60110
Cr-Commit-Position: refs/heads/master@{#28963}

[Toon Verwaest, 2015-06-11 10:52:07]

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

[Toon Verwaest, 2015-06-11 10:52:07]

ptal

[Toon Verwaest, 2015-06-11 10:52:35]

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

[Toon Verwaest, 2015-06-11 10:52:36]

ptal

[Toon Verwaest, 2015-06-11 10:52:54]

ptal

[Jakob Kummerow, 2015-06-11 11:14:28]

https://codereview.chromium.org/1177103003/diff/20001/src/objects.cc
File src/objects.cc (right):

https://codereview.chromium.org/1177103003/diff/20001/src/objects.cc#newcode6408
src/objects.cc:6408: CHECK(GetPropertyAttributes(&it).IsJust());
I'm not a fan of having a Release-mode CHECK here, but since it's old code, I
guess we can keep it.

[Jakob Kummerow, 2015-06-11 11:18:25]

lgtm

[Toon Verwaest, 2015-06-11 16:12:09]

The CQ bit was checked by verwaest@chromium.org

[commit-bot: I haz the power, 2015-06-11 16:12:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1177103003/40001

[commit-bot: I haz the power, 2015-06-11 20:09:23]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-06-11 20:09:37]

Patchset 3 (id:??) landed as
https://crrev.com/83abd09597039c7122e1aab1bfa8851cf0c60110
Cr-Commit-Position: refs/heads/master@{#28963}