The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/03ae5b6069bab8e87953072eeb75a192b6e6d6aa

commit 03ae5b6069bab8e87953072eeb75a192b6e6d6aa
Author: jamescook <jamescook@chromium.org>
Date: Fri Mar 17 03:40:03 2017

Make ui::test::EventGenerator work with PointerEvents in mash

In classic ash PointerWatchers are triggered by an EventHandler attached
to ash::Shell and are triggered in unit tests using EventGenerator.

In mash PointerWatchers are triggered by a PointerWatcherEventRouter
owned by ash::mus::WindowManager. That code path wasn't getting hit in
unit tests using EventGenerator.

Wiring it up fixes SystemTrayTest.PersistentBubble in mash. It will
probably fix several other tests disabled in mash. We'll find those as
we look at them individually -- there's no simple way to re-enable all
those tests to try them.

BUG= 693790 , 695559 
TEST=ash_unittests, mash_unittests SystemTrayTest.PersisentBubble

Review-Url: https://codereview.chromium.org/2752903002
Cr-Commit-Position: refs/heads/master@{#457677}

[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ash/common/system/tray/system_tray_unittest.cc
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ash/mus/window_manager.h
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/aura/env.h
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/aura/test/env_test_helper.h
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/aura/test/event_generator_delegate_aura.cc
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/aura/test/event_generator_delegate_aura.h
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/aura/test/mus/window_tree_client_private.cc
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/aura/test/mus/window_tree_client_private.h
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/events/test/event_generator.cc
[modify] https://crrev.com/03ae5b6069bab8e87953072eeb75a192b6e6d6aa/ui/events/test/event_generator.h

It now dispatches to PointerWatchers via WindowTreeClient in tests.