Remove window/host accessors from WED; IWYU for WTH

ui/views/event_utils_aura.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 "ui/views/event_utils.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/window_event_dispatcher.h"
+#include "ui/aura/window_tree_host.h"
 #include "ui/events/event.h"
 #include "ui/gfx/point.h"
 #include "ui/views/views_delegate.h"
 
 using aura::client::ScreenPositionClient;
 
 namespace views {
 
 bool RepostLocatedEvent(gfx::NativeWindow window,
                         const ui::LocatedEvent& event) {
@@ skipping 39 matching lines @@
   relocated.reset(new ui::MouseEvent(orig));
   relocated->set_location(root_loc);
   relocated->set_root_location(root_loc);
 
   root_window->GetHost()->dispatcher()->RepostEvent(*relocated);
   return true;
 #endif
 }
 
 }  // namespace views