- Introduce proper TickLogEntry and use a separate Timeline object
- Update the main rendering to use SVG for speed
- Separate custom-elements: timeline-track-map and timeline-track-tick
- Revamp flame-chart drawing
- Enable map-transitions overlay
- Use mouse position to infer current log-entry instead of individual
  event handlers
- Fix first timelineLegend column header
- Fixing scrollbar-color for FireFox

Change-Id: I7c53c13366b3e4614b1c5592dfaa69d0654a3b5f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944430
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74987}