Eric Holk a9e7b77672 gpui: Record input-to-frame latency histogram (#53822) ...

Adds instrumentation to track input-to-frame latency in GPUI windows,
helping diagnose input responsiveness issues.

## What this does

- Records the time between when an input event is dispatched and when
the resulting frame is presented, capturing worst-case latency when
multiple events are coalesced into a single frame.
- Tracks how many input events get coalesced per rendered frame.
- Both metrics are stored in
[HdrHistogram](https://docs.rs/hdrhistogram) instances with 3
significant digits of precision.
- Latency is only recorded when the input event actually causes a redraw
(i.e. marks the window dirty), so idle mouse moves and other no-op
events don't skew the data.
- Adds a `Dump Input Latency Histogram` command that opens a buffer with
a formatted report including percentile breakdowns and visual
distribution bars.

## Example output

The report shows percentile latencies, a bucketed distribution with bar
charts, and a per-frame event coalescing breakdown.

Release Notes:

- N/A

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Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Cole Miller <cole@zed.dev>

2026-04-16 17:38:58 +00:00

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src

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Cargo.toml

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LICENSE-GPL

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