While improving Android IME support (da38c1ed), text editor destructors
were updated to explicitly pass keyboard focus elsewhere.
As far as I remember, the change was intended to prevent the text input
system from trying to send input events to components while they were
being destroyed, in which case the TextInputTarget and Component bases
may be 'valid', but the data members referenced by the TextInputTarget
implementation may have been destroyed.
The motivation for removing these lines is that giving away focus and
sending a focus event can cause all components to become unfocused. This
is problematic in the case of slider text editors - pressing 'enter'
will cause the TextEditor to be destroyed, but the parent component will
fail to gain focus, so pressing 'tab' will not have any effect.