GitLab

The crash stack shows OnGridEmpty being called because of WindowDestroyed
while overview is shutting down because of leaving tablet mode.

The feedbacks report say this is play store related, but i have been
unable to reproduce.

This cl introduces a early exit in OnGridEmpty if overview is currently
shutting down. The cause seems like play store is getting destroyed while
in overview tablet and perhaps causing a race condition, but we should
prevent overview from crashing if play store closes its window
unexpectedly.

Test: none
Bug: 881089
Change-Id: I8e8daceb53d2ac56f92662b14d33fd86979dff25
Reviewed-on: https://chromium-review.googlesource.com/1256168Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595734}