FpsMeter keeps the stamp before the last second, so a frame longer
than the span shows as the worst and a bar. The inspector's panel, a
second root out of the app's scope, sits in a FocusScope of its own,
so Tab goes on from Pick. EventLogger takes key downs through an
interceptor, which runs before bindings, and marks its box with a key
context to know focus is inside, so a field's Backspace and Enter log.
Tests hold the stall, Tab both ways through Pick, bound keys in a
field, a key while focus is outside, newest first and a bare border.
ZacharyZhang-NY
4d1a17d29a