Optimization of HTML generated by `cargo timings`

[mox692]

Problem

Sometimes I use cargo timings in my projects, and find that the HTML generated by them often slows down the browser (chrome in my case).
I have also measured the cargo timings in the cargo project for reproduce, and it seems to be taking longer to work as well. (As shown in the attached image, it took about 5s to become operational.)
I guess that the browser is slowing down because the JS that is drawing the canvas is occupying the CPU.

There might be room for optimization of the generated JS.

cargo-timing.html.zip

Proposed Solution

No response

Notes

• cargo 1.75.0 (1d8b05c 2023-11-20)
• Host: x86_64-apple-darwin
• Chrome Version 120.0.6099.216 (Official Build) (x86_64)

I didn't try this in Firefox because of #8850 .

[weihanglo]

Some related exploration about improving the timing HTML people might be interested in: https://rust-lang.zulipchat.com/#narrow/stream/246057-t-cargo/topic/New.20visualizations.20for.20cargo-timing.2Ehtml. Feel free to experiment on modernizing the HTML/JS/CSS part of it.