Change %s in format to %ls.

Change %s in format to %ls.

Though %s works on Windows which is the only OS that compiles this
file, it is non-portable and triggers a DCHECK.

BUG=489801
Committed: https://crrev.com/9f235293834fedd7ffac67e44c3a5f2db56246f7
Cr-Commit-Position: refs/heads/master@{#337971}

[bcwhite, 2015-07-09 00:57:14]

bcwhite@chromium.org changed reviewers:
+ jhawkins@chromium.org

[James Hawkins, 2015-07-09 01:49:46]

lgtm

[grt (UTC plus 2), 2015-07-09 02:24:15]

The CQ bit was checked by grt@chromium.org

[commit-bot: I haz the power, 2015-07-09 02:24:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1221303021/1

[commit-bot: I haz the power, 2015-07-09 02:29:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-09 02:30:47]

Patchset 1 (id:??) landed as
https://crrev.com/9f235293834fedd7ffac67e44c3a5f2db56246f7
Cr-Commit-Position: refs/heads/master@{#337971}