- Use initial color for TimelineTrack chunks
- Use async functions for TimelineTrack setChunkBackgrounds
- Introduce timeSelection setter on TimelinePanel
- Propagate time selection down to the TimelinePanel
- Avoid layout recalculation in TimelineTrack updateSelection

drive-by-cleanups:
- Add common event listeners only to top-level document
- Use console.warn instead of console.error for better debugging in
  DevTools

Bug: v8:10644
Change-Id: Ie4f80f1c6c3f4fa193f8ac01225e0fb76981551d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2497175
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70886}