Remove window/host accessors from WED; IWYU for WTH

ui/aura/test/ui_controls_factory_aura.h

Index: ui/aura/test/ui_controls_factory_aura.h
diff --git a/ui/aura/test/ui_controls_factory_aura.h b/ui/aura/test/ui_controls_factory_aura.h
index 777f0d3661791b8d0da1908295e1e21c670a6843..b6752221a09e78f18815e18e08165683d16f4d0e 100644
--- a/ui/aura/test/ui_controls_factory_aura.h
+++ b/ui/aura/test/ui_controls_factory_aura.h
@@ -8,13 +8,11 @@
 #include "ui/base/test/ui_controls_aura.h"
 
 namespace aura {
-class WindowEventDispatcher;
+class WindowTreeHost;
 
 namespace test {
 
-// TODO(beng): Should be changed to take a WindowTreeHost.
-ui_controls::UIControlsAura* CreateUIControlsAura(
-    WindowEventDispatcher* dispatcher);
+ui_controls::UIControlsAura* CreateUIControlsAura(WindowTreeHost* host);
 
 }  // namespace test
 }  // namespace aura