GitLab

The task posed in the complete callback can be executed
under load if it waits for idle. Explicitly exit upon
animation complete instead.

Bug: None
Test: Test no longer fails under load
Change-Id: Ibef010506fd7a888615b7d2d304d0a04c826d00d
Reviewed-on: https://chromium-review.googlesource.com/c/1357668Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612956}