- Show selection tab-bar
- Hide panels on empty timeline
- Fix legend position in ic list-panel

Bug: v8:10644
Change-Id: I4ef09627ed4de8682adb60f88be38867bc91640d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2584953Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71731}