GitLab

Speculative fix for the linked bug. Was unable to repro manually, but
created a test case that is plausible that has a similar stack trace.

Test: TabletModeOverviewSessionTest.DestroyWindowDuringNudge
Bug: 997335
Change-Id: Ib580740b4c059aa30e44af57e895c27b610f1650
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2225587Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#775261}