DesktopWindowTreeHostMusTest.Deactivate fails flakily in views_mus_unittests with WS2

See work to use test_ws / ws2 in views_mus_unittests here:
  https://chromium-review.googlesource.com/c/chromium/src/+/1138749

[ RUN      ] DesktopWindowTreeHostMusTest.Deactivate
[176717:185077:0717/095623.174177:3968882235834:INFO:service_process_launcher.cc(200)] Launched child process pid=185093, instance=, name=test_ws, user_id=505C0EE9-3013-43C0-82B0-A84F50CF8D84
[185093:185093:0717/095623.422293:3968882484029:ERROR:window_service.cc(30)] Not implemented reached in void ui::ws2::(anonymous namespace)::BindEventInjectorRequest(ui::mojom::EventInjectorRequest)
[185093:185093:0717/095623.422538:3968882484189:ERROR:window_service.cc(34)] Not implemented reached in void ui::ws2::(anonymous namespace)::BindGpuRequest(ui::mojom::GpuRequest)
[185093:185093:0717/095623.422704:3968882484354:ERROR:window_service.cc(34)] Not implemented reached in void ui::ws2::(anonymous namespace)::BindGpuRequest(ui::mojom::GpuRequest)
[185093:185093:0717/095623.422823:3968882484473:ERROR:window_service.cc(39)] Not implemented reached in void ui::ws2::(anonymous namespace)::BindDiscardableSharedMemoryManagerRequest(discardable_memory::mojom::DiscardableSharedMemoryManagerRequest)
[185093:185093:0717/095623.425589:3968882487240:ERROR:window_tree.cc(1316)] Not implemented reached in virtual void ui::ws2::WindowTree::SetHitTestMask(ui::Id, const base::Optional<gfx::Rect> &)
../../ui/views/mus/desktop_window_tree_host_mus_unittest.cc:172: Failure
Value of: widget1->IsActive()
  Actual: false
Expected: true
Stack trace:
#0 0x0000006e147c testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop()
#1 0x0000006e0e59 testing::internal::AssertHelper::operator=()
#2 0x0000004a689c views::DesktopWindowTreeHostMusTest_Deactivate_Test::TestBody()

../../ui/views/mus/desktop_window_tree_host_mus_unittest.cc:173: Failure
Value of: widget1->GetNativeWindow()->HasFocus()
  Actual: false
Expected: true
Stack trace:
#0 0x0000006e147c testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop()
#1 0x0000006e0e59 testing::internal::AssertHelper::operator=()
#2 0x0000004a69b9 views::DesktopWindowTreeHostMusTest_Deactivate_Test::TestBody()

../../ui/views/mus/desktop_window_tree_host_mus_unittest.cc:174: Failure
Expected equality of these values:
  widget_activated()
    Which is: NULL
  widget1.get()
    Which is: 0x157f2c1e23c0
Stack trace:
#0 0x0000006e147c testing::internal::UnitTestImpl::CurrentOsStackTraceExceptTop()
#1 0x0000006e0e59 testing::internal::AssertHelper::operator=()
#2 0x0000004a6b4a views::DesktopWindowTreeHostMusTest_Deactivate_Test::TestBody()

[  FAILED  ] DesktopWindowTreeHostMusTest.Deactivate (277 ms)