Summary:
Fixes T7825. If JX.Scrollbar activates, we sometimes target the wrong node.
(We don't have this issue in the column because it rebuilds a new JX.Scrollbar every time.)
Test Plan:
- Sent messages, no spooky text.
- Loaded page, got scroll to bottom.
- Unplugged all USB devices, restarted browser, repeated.
Reviewers: btrahan, chad
Reviewed By: chad
Subscribers: epriestley
Maniphest Tasks: T7825
Differential Revision: https://secure.phabricator.com/D12413
b40a84c92f