customtabs: Add paranoia to isCallerForegroundOrSelf() due to NPEs in the wild.

customtabs: Add paranoia to isCallerForegroundOrSelf() due to NPEs in the wild.

We have a number of NPEs reported from devices in the
wild. Unfortunately, we only know that they happen on L pre-MR1, and
from warmup(). This commits adds null checks to prevent these from
crashing the client (reported by GSA).

BUG=654705
Review-Url: https://codereview.chromium.org/2404183004
Cr-Commit-Position: refs/heads/master@{#424406}
(cherry picked from commit f974fe4e5a32803b83592a014a82db683cb485f7)

Committed: https://chromium.googlesource.com/chromium/src/+/1d5357e02cda8ed82b7788b76e036937a329460f

[Benoit L, 2016-10-12 14:09:24]

Description was changed from

==========
customtabs: Add paranoia to isCallerForegroundOrSelf() due to NPEs in the wild.

We have a number of NPEs reported from devices in the
wild. Unfortunately, we only know that they happen on L pre-MR1, and
from warmup(). This commits adds null checks to prevent these from
crashing the client (reported by GSA).

BUG=654705

Review-Url: https://codereview.chromium.org/2404183004
Cr-Commit-Position: refs/heads/master@{#424406}
(cherry picked from commit f974fe4e5a32803b83592a014a82db683cb485f7)
==========

to

==========
customtabs: Add paranoia to isCallerForegroundOrSelf() due to NPEs in the wild.

We have a number of NPEs reported from devices in the
wild. Unfortunately, we only know that they happen on L pre-MR1, and
from warmup(). This commits adds null checks to prevent these from
crashing the client (reported by GSA).

BUG=654705

Review-Url: https://codereview.chromium.org/2404183004
Cr-Commit-Position: refs/heads/master@{#424406}
(cherry picked from commit f974fe4e5a32803b83592a014a82db683cb485f7)

Committed:
https://chromium.googlesource.com/chromium/src/+/1d5357e02cda8ed82b7788b76e03...
==========

[Benoit L, 2016-10-12 14:09:26]

Committed patchset #1 (id:1) manually as
1d5357e02cda8ed82b7788b76e036937a329460f.