This is step 1 of a four-step change which will move where
updateSelection is called in regular text fields. The new
behavior will be to call it for each actual batch of
changes, instead of doing it in the render loop which leads
to both false positives and true negatives.
Bug: 8000119
Change-Id: I17bd91a129b18d5451fe1d8e7794ae20165de309
df7c72f68c