GitLab

This CL also adds differentiation between a loading and a waiting state,
each displaying a spinner in their own colors and directions, similar
to how the native tab strip works.

This CL also updates types to allow for the new data.

Bug: 1004985
Change-Id: I1b9361b3796e369d683b8f63c6a2026364d439f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1848573Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: John Lee <johntlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#704743}