GitLab

Previously in this small refactor CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1769025,
we introduced a bug that StopSequence moves a tracker to the list of
|removal_tracker_|, and that NotifyFramePresented will never apply to
that list.

This CL fixes the bug and added unit testing.

Bug: None
Change-Id: I37a39994b26c5627e5fc1add9d9688cbf69184a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1774313
Commit-Queue: Xida Chen <xidachen@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692095}