Hyatt asked me to port break_lines.cpp to "use ICU", but it can be ported to use TextBreakIterator.h and hence be more-or-less platform independent.
Created attachment 12324 [details] patch, including change log -- passes all layout tests
Comment on attachment 12324 [details] patch, including change log -- passes all layout tests r=me. Run tests!
Be sure to test Thai word breaks! See <http://www.opensource.apple.com/darwinsource/10.4.8.ppc/ICU-6.2.9/icuSources/test/thaitest/> for possible test data.
*** This bug has been marked as a duplicate of 4628 ***