Merge \"Add bound checks to utf16_to_utf8 am: bce11021b2 am: 008120497b am: bab3334226 am: ff58d7c918  -s ours am: 437776ac65 am: 7c19aa73f7\" into nyc-mr1-dev-plus-aosp
am: 1072978c6a

Change-Id: I1b5c8149c042b29f1b860efc56dc61dab25a04b5