Steps to Reproduce

1. Run https://flutter.github.io/samples/web/simplistic_editor/#/ in a browser
2. Set cursor on right after first character (after 'T')
3. Hit suppron keyboard

Expected results: Deletion Delta Offset = (1,2)

Actual results: Deletion Delta Offset = (0,1)

Code sample: https://github.com/flutter/samples/blob/main/simplistic_editor