CPP: Fix compilation error on Windows.
CPP: Fix compilation error on Windows.

This appears when the library is built in Chromium.

R=lararennie@google.com

Review URL: https://codereview.appspot.com/10286044
oneminot/libphonenumber,oneminot/libphonenumber,oneminot/libphonenumber,oneminot/libphonenumber