Summary:
Depends on D19166. Ref T13088. When the user scrolls away from a followed log, break the focus lock.
Let users stop following a live log.
Show when lines are added more clearly.
Don't refresh quite as quickly give users a better shot at clicking the stop button.
These behaviors can probably be refined but are at least more plausible and less actively user-hostile than the first version of this behavior was.
Test Plan: Used `write-log --rate` to write a large log slowly. Clicked "Follow Log", followed for a bit. Scrolled away, still got live updates but no more scroll lock. Clicked stop, no more updates.
Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam
Maniphest Tasks: T13088
Differential Revision: https://secure.phabricator.com/D19167