Plugin Power Saver: Fix race between GIN bindings and destruction

Plugin Power Saver: Fix race between GIN bindings and destruction

Sometimes the plugin.didFinishIconRepositionForTesting() C++ handler
triggers after the plugin has been marked for deletion.

This leads to a use-after-free crash as reported in the bug. This CL
fixes that by checking for plugin() being nullptr.

Other GIN callbacks use this check already to handle this case.

BUG=512140
Committed: https://crrev.com/2c329c9ed91c9aeae56633a50128f4d1b9abf927
Cr-Commit-Position: refs/heads/master@{#432550}

[tommycli, 2016-11-15 23:01:51]

tommycli@chromium.org changed reviewers:
+ bauerb@chromium.org

[tommycli, 2016-11-15 23:01:51]

bauerb: PTAL, thanks!

[tommycli, 2016-11-15 23:05:43]

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

[commit-bot: I haz the power, 2016-11-15 23:06:38]

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, 2016-11-15 23:29:29]

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

[commit-bot: I haz the power, 2016-11-15 23:29:29]

Dry run: Try jobs failed on following builders:
  cast_shell_linux on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linu...)

[tommycli, 2016-11-15 23:29:54]

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

[commit-bot: I haz the power, 2016-11-15 23:30:39]

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, 2016-11-16 00:14:22]

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

[commit-bot: I haz the power, 2016-11-16 00:14:23]

Dry run: This issue passed the CQ dry run.

[Bernhard Bauer, 2016-11-16 17:40:47]

RS LGTM

[tommycli, 2016-11-16 17:52:40]

The CQ bit was checked by tommycli@chromium.org

[commit-bot: I haz the power, 2016-11-16 17:53:05]

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, 2016-11-16 18:00:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-16 18:20:06]

Description was changed from

==========
Plugin Power Saver: Fix race between GIN bindings and destruction

Sometimes the plugin.didFinishIconRepositionForTesting() C++ handler
triggers after the plugin has been marked for deletion.

This leads to a use-after-free crash as reported in the bug. This CL
fixes that by checking for plugin() being nullptr.

Other GIN callbacks use this check already to handle this case.

BUG=512140
==========

to

==========
Plugin Power Saver: Fix race between GIN bindings and destruction

Sometimes the plugin.didFinishIconRepositionForTesting() C++ handler
triggers after the plugin has been marked for deletion.

This leads to a use-after-free crash as reported in the bug. This CL
fixes that by checking for plugin() being nullptr.

Other GIN callbacks use this check already to handle this case.

BUG=512140

Committed: https://crrev.com/2c329c9ed91c9aeae56633a50128f4d1b9abf927
Cr-Commit-Position: refs/heads/master@{#432550}
==========

[commit-bot: I haz the power, 2016-11-16 18:20:08]

Patchset 1 (id:??) landed as
https://crrev.com/2c329c9ed91c9aeae56633a50128f4d1b9abf927
Cr-Commit-Position: refs/heads/master@{#432550}