Remove window/host accessors from WED; IWYU for WTH

ui/aura/test/ui_controls_factory_aurawin.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "ui/aura/test/ui_controls_factory_aura.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_event_dispatcher.h"
+#include "ui/aura/window_tree_host.h"
 #include "ui/base/test/ui_controls_aura.h"
 #include "ui/base/test/ui_controls_internal_win.h"
 
 namespace aura {
 namespace test {
 
 namespace {
 
 using ui_controls::DOWN;
 using ui_controls::LEFT;
@@ skipping 56 matching lines @@
     // On windows, posting UI events is synchronous so just post the closure.
     base::MessageLoopForUI::current()->PostTask(FROM_HERE, closure);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(UIControlsWin);
 };
 
 }  // namespace
 
-UIControlsAura* CreateUIControlsAura(WindowEventDispatcher* dispatcher) {
+UIControlsAura* CreateUIControlsAura(WindowTreeHost* host) {
   return new UIControlsWin();
 }
 
 }  // namespace test
 }  // namespace aura