The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f535f3e8476a4727232607d5d887409686405f45

commit f535f3e8476a4727232607d5d887409686405f45
Author: Elliot Glaysher <erg@chromium.org>
Date: Wed Jul 12 00:31:19 2017

Keep track of mouse events enabled in mus mode.

For mash, we'll have to port the current logic in CompountEventFilter to the
window server for keeping track of the mouse event enabled state, but for mus,
we can just use the existing cursor_manager().

Bug:  734808 , 637853 
Change-Id: I4b6a084732b643b6c8f94f091ee60852d9d07597
Reviewed-on: https://chromium-review.googlesource.com/565351
Commit-Queue: Elliot Glaysher <erg@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485748}
[modify] https://crrev.com/f535f3e8476a4727232607d5d887409686405f45/ash/mus/bridge/shell_port_mash.cc
[modify] https://crrev.com/f535f3e8476a4727232607d5d887409686405f45/testing/buildbot/filters/ash_unittests_mus.filter