Reland of Improves focus/activation for aura-mus and DesktopNativeWidgetAura

ui/aura/test/aura_test_helper.cc

Index: ui/aura/test/aura_test_helper.cc
diff --git a/ui/aura/test/aura_test_helper.cc b/ui/aura/test/aura_test_helper.cc
index bbf733e8db0f1a002103f30d25fb3124b5fb5da4..501c3adf816238afd07b9c30db8891db1e14936d 100644
--- a/ui/aura/test/aura_test_helper.cc
+++ b/ui/aura/test/aura_test_helper.cc
@@ -95,6 +95,7 @@
     env_ = Env::CreateInstance(window_impl_factory);
   else
     EnvTestHelper(Env::GetInstance()).SetWindowPortFactory(window_impl_factory);
+  Env::GetInstance()->SetActiveFocusClient(focus_client_.get(), nullptr);
   Env::GetInstance()->set_context_factory(context_factory);
   // Unit tests generally don't want to query the system, rather use the state
   // from RootWindow.
@@ -140,6 +141,7 @@
   ui::test::ResetXCursorCache();
 #endif
 
+  Env::GetInstance()->SetActiveFocusClient(nullptr, nullptr);
   window_tree_client_setup_.reset();
   focus_client_.reset();
   capture_client_.reset();