WebVR: Don't crash when receiving null image from rendering context.

WebVR: Don't crash when receiving null image from rendering context.

Not sure why/how this happens, but I was seeing this infrequently on  https://with.in/watch/under-neon-lights/

BUG=718501
Review-Url: https://codereview.chromium.org/2862883002
Cr-Commit-Position: refs/heads/master@{#469517}
Committed: https://chromium.googlesource.com/chromium/src/+/a1215009f69ac267d13b072cc2d4c9cda7155fee

[mthiesse, 2017-05-04 18:00:00]

Description was changed from

==========
WebVR: Don't crash when receiving null image from rendering context.

Not sure why/how this happens, but I was seeing this infrequently on 
https://with.in/watch/under-neon-lights/

BUG=
==========

to

==========
WebVR: Don't crash when receiving null image from rendering context.

Not sure why/how this happens, but I was seeing this infrequently on 
https://with.in/watch/under-neon-lights/

BUG=718501
==========

[mthiesse, 2017-05-04 18:00:18]

mthiesse@chromium.org changed reviewers:
+ bajones@chromium.org, klausw@chromium.org

[mthiesse, 2017-05-04 18:00:19]

PTAL

[bajones, 2017-05-04 21:17:15]

lgtm

[mthiesse, 2017-05-04 21:17:54]

The CQ bit was checked by mthiesse@chromium.org

[commit-bot: I haz the power, 2017-05-04 21:18:49]

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, 2017-05-04 23:29:26]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493932674245100, "parent_rev":
"1f58e951e440d1a57e94536ed34aae1715eedf21", "commit_rev":
"a1215009f69ac267d13b072cc2d4c9cda7155fee"}

[commit-bot: I haz the power, 2017-05-04 23:29:33]

Description was changed from

==========
WebVR: Don't crash when receiving null image from rendering context.

Not sure why/how this happens, but I was seeing this infrequently on 
https://with.in/watch/under-neon-lights/

BUG=718501
==========

to

==========
WebVR: Don't crash when receiving null image from rendering context.

Not sure why/how this happens, but I was seeing this infrequently on 
https://with.in/watch/under-neon-lights/

BUG=718501

Review-Url: https://codereview.chromium.org/2862883002
Cr-Commit-Position: refs/heads/master@{#469517}
Committed:
https://chromium.googlesource.com/chromium/src/+/a1215009f69ac267d13b072cc2d4...
==========

[commit-bot: I haz the power, 2017-05-04 23:29:34]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/a1215009f69ac267d13b072cc2d4...