Fix NFC crasher from accessing a destroyed activity.

Fix NFC crasher from accessing a destroyed activity.

While this works, it would be better to have a clearer signal that
the Activity died (or is in the process of shutting down) so we
could make a better timed decision to disable NFC reading.

Also note that Activity#isDestroyed() is only available in
JELLY_BEAN_MR1, so this is not the best solution for all device
implementations that need to determine this.

BUG=640890
Committed: https://crrev.com/1ff2cc181eb07396527b76ba2e15d48684c27d15
Cr-Commit-Position: refs/heads/master@{#415441}

[Ted C, 2016-08-30 20:48:39]

tedchoc@chromium.org changed reviewers:
+ reillyg@chromium.org

[Ted C, 2016-08-30 20:48:40]

PTAL

[Reilly Grant (use Gerrit), 2016-08-30 20:51:26]

lgtm

[Ted C, 2016-08-30 20:52:55]

The CQ bit was checked by tedchoc@chromium.org

[commit-bot: I haz the power, 2016-08-30 20:53:51]

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, 2016-08-30 21:47:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-30 21:51:34]

Description was changed from

==========
Fix NFC crasher from accessing a destroyed activity.

While this works, it would be better to have a clearer signal that
the Activity died (or is in the process of shutting down) so we
could make a better timed decision to disable NFC reading.

Also note that Activity#isDestroyed() is only available in
JELLY_BEAN_MR1, so this is not the best solution for all device
implementations that need to determine this.

BUG=640890
==========

to

==========
Fix NFC crasher from accessing a destroyed activity.

While this works, it would be better to have a clearer signal that
the Activity died (or is in the process of shutting down) so we
could make a better timed decision to disable NFC reading.

Also note that Activity#isDestroyed() is only available in
JELLY_BEAN_MR1, so this is not the best solution for all device
implementations that need to determine this.

BUG=640890

Committed: https://crrev.com/1ff2cc181eb07396527b76ba2e15d48684c27d15
Cr-Commit-Position: refs/heads/master@{#415441}
==========

[commit-bot: I haz the power, 2016-08-30 21:51:35]

Patchset 1 (id:??) landed as
https://crrev.com/1ff2cc181eb07396527b76ba2e15d48684c27d15
Cr-Commit-Position: refs/heads/master@{#415441}