GitLab

Prevents use-after-free if ContextMenuController gets destroyed while
the context menu is running (nested runloop or as a result of using the
context menu).

Bug: chromium:1003313
Change-Id: Ib289adf97cd1b5d27507ee4d4c581c1bb3f51bdf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815828
Commit-Queue: Peter Boström <pbos@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699860}