Revert "Always call handleTextSelectionChange() on descendants"
Revert "Always call handleTextSelectionChange() on descendants"

This reverts commit 5233b3562cce9f26e9d2296dfac616e8f94ef9e3.

It introduced unwanted chattiness.

GNOME/orca,GNOME/orca,GNOME/orca,GNOME/orca