ticket:10884: Apply API proposal from 11 Jun ICU meeting.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@35861 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10884: Applied review comments from Andy Heninger.

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@35862 251d0590-4201-4cf1-90de-194747b24ca1