Icu setText method keeps pointer to text, it doesn't copy it so we have to keep text around for the lifetime of the break iterator object,
or next setText operation.

Review URL: http://codereview.chromium.org/6609038

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7063 ce2b1a6d-e550-0410-aec6-3dcde31c8c00