GitLab

This change fixes crbug/998959 by setting inSystemMenu_
to false when the system menu (i.e. the right-click
or context menu) is removed from the page.

Bug: 998959
Change-Id: I391b634217513247c4f4215f5a47ffb028886bc5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1775381Reviewed-by: Anastasia Helfinstein <anastasi@google.com>
Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Commit-Queue: Sophie Yang <sophyang@google.com>
Cr-Commit-Position: refs/heads/master@{#691780}