Serializer: clear next link in weak cells.

Serializer: clear next link in weak cells.

If we do not clear next links during serialization, the
serializer would simply follow those links and serialize
arbitrary objects held by weak cells. This breaks the
invariant in the code serializer, which crashes if it
sees context-dependent objects.

R=ulan@chromium.org
BUG=chromium:503552
LOG=Y

Committed: https://crrev.com/f1982eb49083d0063214ffa0f9f92c0609ae31cc
Cr-Commit-Position: refs/heads/master@{#29255}

[Yang, 2015-06-24 11:05:03]

Ulan, please review.

This has to be landed before https://codereview.chromium.org/1211453002/

[ulan, 2015-06-24 11:11:19]

lgtm if comments are addressed:

https://codereview.chromium.org/1203973002/diff/1/src/snapshot/serialize.cc
File src/snapshot/serialize.cc (right):

https://codereview.chromium.org/1203973002/diff/1/src/snapshot/serialize.cc#n...
src/snapshot/serialize.cc:1866: if (weak_cell_) weak_cell_->set_next(next_);
set_next(next_, UPDATE_WEAK_WRITE_BARRIER)

https://codereview.chromium.org/1203973002/diff/1/src/snapshot/serialize.cc#n...
src/snapshot/serialize.cc:1934: UnlinkWeakCellScope unlink_weak_cell(object_);
Please add disallow allocation scope here or in UnlinkWeakCellScope.

https://codereview.chromium.org/1203973002/diff/1/src/snapshot/serialize.cc#n...
src/snapshot/serialize.cc:1960: UnlinkWeakCellScope unlink_weak_cell(object_);
Please add disallow allocation scope here or in UnlinkWeakCellScope.

[Yang, 2015-06-24 11:23:45]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2015-06-24 11:23:46]

The patchset sent to the CQ was uploaded after l-g-t-m from ulan@chromium.org
Link to the patchset: https://codereview.chromium.org/1203973002/#ps20001
(title: "address comments")

[commit-bot: I haz the power, 2015-06-24 11:23:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1203973002/20001

[commit-bot: I haz the power, 2015-06-24 11:26:59]

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

[commit-bot: I haz the power, 2015-06-24 11:27:00]

Exceeded global retry quota

[Yang, 2015-06-24 11:44:42]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2015-06-24 11:44:43]

The patchset sent to the CQ was uploaded after l-g-t-m from ulan@chromium.org
Link to the patchset: https://codereview.chromium.org/1203973002/#ps40001
(title: "fix build")

[commit-bot: I haz the power, 2015-06-24 11:44:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1203973002/40001

[commit-bot: I haz the power, 2015-06-24 12:22:41]

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

[commit-bot: I haz the power, 2015-06-24 12:22:42]

Try jobs failed on following builders:
  v8_linux64_asan_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_asan_rel/builds/...)

[Yang, 2015-06-24 13:55:48]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2015-06-24 13:55:48]

The patchset sent to the CQ was uploaded after l-g-t-m from ulan@chromium.org
Link to the patchset: https://codereview.chromium.org/1203973002/#ps60001
(title: "fix asan failure")

[commit-bot: I haz the power, 2015-06-24 13:56:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1203973002/60001

[commit-bot: I haz the power, 2015-06-24 14:26:39]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-06-24 14:26:54]

Patchset 4 (id:??) landed as
https://crrev.com/f1982eb49083d0063214ffa0f9f92c0609ae31cc
Cr-Commit-Position: refs/heads/master@{#29255}