[Cronet] Fix build failure in net_string_util_icu_alternatives_ios.mm

Looks caused by crrev.com/652649

Bug: 820198
Change-Id: Ifa4633140962e1a88097a466370d12f3d39065cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1576436
Commit-Queue: Paul Jensen <pauljensen@chromium.org>
Commit-Queue: Misha Efimov <mef@chromium.org>
Auto-Submit: Paul Jensen <pauljensen@chromium.org>
Reviewed-by: Misha Efimov <mef@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652835}
1 file changed