Fix DCHECK_IS_ON() iOS build

Fix DCHECK_IS_ON() iOS build

Extracted from https://codereview.chromium.org/2886803002/

BUG=722827
TBR=sdefresne

Review-Url: https://codereview.chromium.org/2885403002
Cr-Commit-Position: refs/heads/master@{#472445}
Committed: https://chromium.googlesource.com/chromium/src/+/ab611961b4bf7919c37a26491cc79376a4b07f7b

[gab, 2017-05-17 13:45:24]

Description was changed from

==========
Fix DCHECK_IS_ON() iOS build

Extracted from https://codereview.chromium.org/2886803002/

BUG=722827
==========

to

==========
Fix DCHECK_IS_ON() iOS build

Extracted from https://codereview.chromium.org/2886803002/

BUG=722827
TBR=sdefresne
==========

[gab, 2017-05-17 13:45:24]

gab@chromium.org changed reviewers:
+ sdefresne@chromium.org

[gab, 2017-05-17 13:45:38]

iOS fix extracted from https://codereview.chromium.org/2886803002/

TBR sdfresne

[gab, 2017-05-17 13:45:41]

The CQ bit was checked by gab@chromium.org

[commit-bot: I haz the power, 2017-05-17 13:46:17]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[sdefresne, 2017-05-17 13:58:10]

On 2017/05/17 13:46:17, commit-bot: I haz the power wrote:
> CQ is trying da patch.
> 
> Follow status at:
>
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

This dupes my CL https://codereview.chromium.org/2890743002/ (already ready to
land as soon as you stamp it).

[sdefresne, 2017-05-17 13:59:12]

lgtm

[commit-bot: I haz the power, 2017-05-17 14:01:08]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495028741485470, "parent_rev":
"b682323da83cc2b5cc06e4e21516a2dbe3883acf", "commit_rev":
"ab611961b4bf7919c37a26491cc79376a4b07f7b"}

[commit-bot: I haz the power, 2017-05-17 14:01:18]

Description was changed from

==========
Fix DCHECK_IS_ON() iOS build

Extracted from https://codereview.chromium.org/2886803002/

BUG=722827
TBR=sdefresne
==========

to

==========
Fix DCHECK_IS_ON() iOS build

Extracted from https://codereview.chromium.org/2886803002/

BUG=722827
TBR=sdefresne

Review-Url: https://codereview.chromium.org/2885403002
Cr-Commit-Position: refs/heads/master@{#472445}
Committed:
https://chromium.googlesource.com/chromium/src/+/ab611961b4bf7919c37a26491cc7...
==========

[commit-bot: I haz the power, 2017-05-17 14:01:19]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/ab611961b4bf7919c37a26491cc7...