Fix performance regression of heap snapshot generator that was

Fix performance regression of heap snapshot generator that was
introduced in https://crrev.com/72f884a19fa4434bba6fc0e013ec4ea0a2366893

The regression comes from adding the next weak field of AllocationSite
as a hidden reference into the snapshot.

Before 72f884 the reference was implicitly ignored because the body
descriptor of AllocationSite did not include it.

This patch explicitly skip the next weak field of AllocationSite.

BUG=chromium:630027
Committed: https://crrev.com/ea45a210a62d24cdb6b17d6374ed7648691fa6c3
Cr-Commit-Position: refs/heads/master@{#38211}

[ulan, 2016-07-27 16:52:30]

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

[ulan, 2016-07-27 16:52:30]

PTAL. More context is in crbug.com/630027.

[alph, 2016-07-27 19:10:27]

Thanks for fixing! lgtm

[alph, 2016-07-27 19:10:31]

The CQ bit was checked by alph@chromium.org

[commit-bot: I haz the power, 2016-07-27 19:10:36]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-27 19:45:33]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-27 19:45:34]

Try jobs failed on following builders:
  v8_win_nosnap_shared_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_nosnap_shared_rel_ng...)
  v8_win_nosnap_shared_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_nosnap_shared_rel_ng...)

[ulan, 2016-07-29 10:57:00]

The CQ bit was checked by ulan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-29 10:57:05]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-29 11:16:50]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-29 11:16:51]

Dry run: This issue passed the CQ dry run.

[ulan, 2016-08-01 12:59:51]

The CQ bit was checked by ulan@chromium.org

[ulan, 2016-08-01 12:59:52]

The patchset sent to the CQ was uploaded after l-g-t-m from alph@chromium.org
Link to the patchset: https://codereview.chromium.org/2189643004/#ps40001
(title: "comments")

[commit-bot: I haz the power, 2016-08-01 12:59:59]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-01 13:31:03]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-08-01 13:34:36]

Description was changed from

==========
Fix performance regression of heap snapshot generator that was
introduced in https://crrev.com/72f884a19fa4434bba6fc0e013ec4ea0a2366893

The regression comes from adding the next weak field of AllocationSite
as a hidden reference into the snapshot.

Before 72f884 the reference was implicitly ignored because the body
descriptor of AllocationSite did not include it.

This patch explicitly skip the next weak field of AllocationSite.

BUG=chromium:630027
==========

to

==========
Fix performance regression of heap snapshot generator that was
introduced in https://crrev.com/72f884a19fa4434bba6fc0e013ec4ea0a2366893

The regression comes from adding the next weak field of AllocationSite
as a hidden reference into the snapshot.

Before 72f884 the reference was implicitly ignored because the body
descriptor of AllocationSite did not include it.

This patch explicitly skip the next weak field of AllocationSite.

BUG=chromium:630027

Committed: https://crrev.com/ea45a210a62d24cdb6b17d6374ed7648691fa6c3
Cr-Commit-Position: refs/heads/master@{#38211}
==========

[commit-bot: I haz the power, 2016-08-01 13:34:37]

Patchset 3 (id:??) landed as
https://crrev.com/ea45a210a62d24cdb6b17d6374ed7648691fa6c3
Cr-Commit-Position: refs/heads/master@{#38211}