Catch null return value from computeComputedStyle.

Catch null return value from computeComputedStyle.

This patch is in response to a Crash Report, so I don't have a repro. I
haven't been able to trigger the condition locally. However it seems
that other call sites to ensureComputedStyle (which computeComputedStyle
calls through to) perform a null check, so it's sensible that we need to
here as well.

Unfortunately, no repro means no test case :(

BUG=571040
Committed: https://crrev.com/58099385dfca252653e833ba1a6e3e83b196e402
Cr-Commit-Position: refs/heads/master@{#367288}

[shans, 2015-12-27 03:10:55]

shans@chromium.org changed reviewers:
+ dstockwell@chromium.org

[shans, 2015-12-27 03:11:00]

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

[commit-bot: I haz the power, 2015-12-27 03:11:05]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1547183002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1547183002/1

[commit-bot: I haz the power, 2015-12-27 04:45:19]

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

[commit-bot: I haz the power, 2015-12-27 04:45:19]

Dry run: This issue passed the CQ dry run.

[dstockwell, 2016-01-03 21:42:09]

lgtm

[shans, 2016-01-03 22:01:21]

The CQ bit was checked by shans@chromium.org

[commit-bot: I haz the power, 2016-01-03 22:02:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1547183002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1547183002/1

[commit-bot: I haz the power, 2016-01-03 23:19:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-01-03 23:20:14]

Description was changed from

==========
Catch null return value from computeComputedStyle.

This patch is in response to a Crash Report, so I don't have a repro. I
haven't been able to trigger the condition locally. However it seems
that other call sites to ensureComputedStyle (which computeComputedStyle
calls through to) perform a null check, so it's sensible that we need to
here as well.

Unfortunately, no repro means no test case :(

BUG=571040
==========

to

==========
Catch null return value from computeComputedStyle.

This patch is in response to a Crash Report, so I don't have a repro. I
haven't been able to trigger the condition locally. However it seems
that other call sites to ensureComputedStyle (which computeComputedStyle
calls through to) perform a null check, so it's sensible that we need to
here as well.

Unfortunately, no repro means no test case :(

BUG=571040

Committed: https://crrev.com/58099385dfca252653e833ba1a6e3e83b196e402
Cr-Commit-Position: refs/heads/master@{#367288}
==========

[commit-bot: I haz the power, 2016-01-03 23:20:14]

Patchset 1 (id:??) landed as
https://crrev.com/58099385dfca252653e833ba1a6e3e83b196e402
Cr-Commit-Position: refs/heads/master@{#367288}

[rune, 2016-01-04 10:29:22]

rune@opera.com changed reviewers:
+ rune@opera.com

[rune, 2016-01-04 10:29:23]

I've made a test here:

https://codereview.chromium.org/1553083002/