Fix null pointer dereference in ipc_boostrap

Fix null pointer dereference in ipc_boostrap

This was being hit when a sync message is dequeued and handled, and the
receiver endpoint immediately destroys itself.

BUG=714192
Review-Url: https://codereview.chromium.org/2834493008
Cr-Commit-Position: refs/heads/master@{#466383}
Committed: https://chromium.googlesource.com/chromium/src/+/1af8d6abdae50ae8b8df88c7796a9d042461b4d0

[Charlie Harrison, 2017-04-21 14:55:20]

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

[commit-bot: I haz the power, 2017-04-21 14:55:37]

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

[Charlie Harrison, 2017-04-21 15:22:56]

Description was changed from

==========
Fix null pointer dereference in ipc_boostrap

BUG=TODO
==========

to

==========
Fix null pointer dereference in ipc_boostrap

This was being hit when a sync message is dequeued and handled, and the
receiver endpoint immediately destroys itself.

BUG=none
==========

[Charlie Harrison, 2017-04-21 15:24:58]

csharrison@chromium.org changed reviewers:
+ rockot@chromium.org

[Charlie Harrison, 2017-04-21 15:24:59]

Ken, would you PTAL?

I was hitting this issue in the window.open CL (which will be a dependent PS of
this one) with the following JS code:

window.open();
deleteSelf();

Somehow it looked like the window.open() call was being successfully handled,
but we still went down this code path after the frame went away (and the
endpoint detached).

[commit-bot: I haz the power, 2017-04-21 15:52:15]

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

[commit-bot: I haz the power, 2017-04-21 15:52:16]

Dry run: This issue passed the CQ dry run.

[Ken Rockot(use gerrit already), 2017-04-21 17:39:12]

Oof, nice catch. LGTM and thanks!

[Charlie Harrison, 2017-04-21 17:41:08]

Thanks, I'll go ahead and land this but we should open up a bug to add a
regression test. I tried briefly but I am very unfamiliar with the code.

[Charlie Harrison, 2017-04-21 17:41:29]

The CQ bit was checked by csharrison@chromium.org

[commit-bot: I haz the power, 2017-04-21 17:41:52]

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

[Charlie Harrison, 2017-04-21 17:43:53]

Description was changed from

==========
Fix null pointer dereference in ipc_boostrap

This was being hit when a sync message is dequeued and handled, and the
receiver endpoint immediately destroys itself.

BUG=none
==========

to

==========
Fix null pointer dereference in ipc_boostrap

This was being hit when a sync message is dequeued and handled, and the
receiver endpoint immediately destroys itself.

BUG=714192
==========

[commit-bot: I haz the power, 2017-04-21 17:47:26]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1492796489443600, "parent_rev":
"84018db5a3ed03a95d03f414fcfce5dddbbc6176", "commit_rev":
"1af8d6abdae50ae8b8df88c7796a9d042461b4d0"}

[commit-bot: I haz the power, 2017-04-21 17:47:36]

Description was changed from

==========
Fix null pointer dereference in ipc_boostrap

This was being hit when a sync message is dequeued and handled, and the
receiver endpoint immediately destroys itself.

BUG=714192
==========

to

==========
Fix null pointer dereference in ipc_boostrap

This was being hit when a sync message is dequeued and handled, and the
receiver endpoint immediately destroys itself.

BUG=714192

Review-Url: https://codereview.chromium.org/2834493008
Cr-Commit-Position: refs/heads/master@{#466383}
Committed:
https://chromium.googlesource.com/chromium/src/+/1af8d6abdae50ae8b8df88c7796a...
==========

[commit-bot: I haz the power, 2017-04-21 17:47:37]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/1af8d6abdae50ae8b8df88c7796a...