dillon1000/react

[DevTools] Add a little bar indicating time span of an async entry relative to others (#34016)

Stacked on #34012.

This shows a time track for when some I/O started and when it finished
relative to other I/O in the same component (or later in the same
suspense boundary).

This is not meant to be a precise visualization since the data might be
misleading if you're running this in dev which has other perf
characteristics anyway. It's just meant to be a general way to orient
yourself in the data.

We can also highlight rejected promises here.

The color scheme is the same as Chrome's current Performance Track
colors to add continuity but those could change.

<img width="478" height="480" alt="Screenshot 2025-07-27 at 11 48 03 PM"
src="https://github.com/user-attachments/assets/545dd591-a91f-4c47-be96-41d80f09a94a"
/>