Final small cleanup.

This does not change anything in the practice since the only
time where timing of the endBatchEdit() call matters is when
sendCurrentText is a no-op. Still, it's theoretically correct
to do it in this order.
This concludes a four-step refactoring moving where the
editor calls updateSelection to warn the IME of a cursor move.

Change-Id: I3109a482ec1d4cd9b4ffb33cc363a4ce5128861a