[Presentation API] check if frame() is null before accessing presentation.receiver attr

[Presentation API] check if frame() is null before accessing presentation.receiver attr

We have seen random crashes when accessing navigator.presentation.receiver attribute. We suspect that is caused by accessing attribute after frame() get destroyed. Add null check and only access frame() for the first time.

BUG=657479
Committed: https://crrev.com/1399b5bdf21388b0b1a77c01473431988035e587
Cr-Commit-Position: refs/heads/master@{#432713}

[zhaobin, 2016-11-15 22:55:08]

zhaobin@chromium.org changed reviewers:
+ imcheng@chromium.org, mfoltz@chromium.org, mlamouri@chromium.org

[haraken, 2016-11-15 23:22:23]

LGTM

[mlamouri (slow - plz ping), 2016-11-16 18:59:21]

mlamouri@chromium.org changed reviewers:
+ haraken@chromium.org

[mlamouri (slow - plz ping), 2016-11-16 18:59:21]

lgtm

[zhaobin, 2016-11-16 23:09:27]

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

[commit-bot: I haz the power, 2016-11-16 23:10:47]

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, 2016-11-17 01:38:17]

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

[commit-bot: I haz the power, 2016-11-17 01:38:18]

Dry run: This issue passed the CQ dry run.

[zhaobin, 2016-11-17 01:41:36]

The CQ bit was checked by zhaobin@chromium.org

[commit-bot: I haz the power, 2016-11-17 01:43:03]

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, 2016-11-17 02:41:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-17 02:50:18]

Description was changed from

==========
[Presentation API] check if frame() is null before accessing
presentation.receiver attr

We have seen random crashes when accessing navigator.presentation.receiver
attribute. We suspect that is caused by accessing attribute after frame() get
destroyed. Add null check and only access frame() for the first time.

BUG=657479
==========

to

==========
[Presentation API] check if frame() is null before accessing
presentation.receiver attr

We have seen random crashes when accessing navigator.presentation.receiver
attribute. We suspect that is caused by accessing attribute after frame() get
destroyed. Add null check and only access frame() for the first time.

BUG=657479

Committed: https://crrev.com/1399b5bdf21388b0b1a77c01473431988035e587
Cr-Commit-Position: refs/heads/master@{#432713}
==========

[commit-bot: I haz the power, 2016-11-17 02:50:18]

Patchset 1 (id:??) landed as
https://crrev.com/1399b5bdf21388b0b1a77c01473431988035e587
Cr-Commit-Position: refs/heads/master@{#432713}