- Limit transition view to 200 maps
- Avoid displaying parent maps multiple times
- Fix timeline-track selection, slow dragging works now

Bug: v8:10644
Change-Id: I2106ea8240977e0ea65083d296977ab0272304d3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485851
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70677}