Avoid two targeting phases in aura client-lib and EventProcessor.

ash/root_window_controller.cc

 // Copyright (c) 2012 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 "ash/root_window_controller.h"
 
 #include <algorithm>
 #include <queue>
 #include <vector>
 
@@ skipping 468 matching lines @@
 
 WmWindow* RootWindowController::FindEventTarget(
     const gfx::Point& location_in_screen) {
   gfx::Point location_in_root(location_in_screen);
   aura::Window* root_window = GetRootWindow();
   ::wm::ConvertPointFromScreen(root_window, &location_in_root);
   ui::MouseEvent test_event(ui::ET_MOUSE_MOVED, location_in_root,
                             location_in_root, ui::EventTimeForNow(),
                             ui::EF_NONE, ui::EF_NONE);
   ui::EventTarget* event_handler =
-      static_cast<ui::EventTarget*>(root_window)
-          ->GetEventTargeter()
+      root_window->GetHost()
+          ->dispatcher()
+          ->GetDefaultEventTargeter()
           ->FindTargetForEvent(root_window, &test_event);
   return WmWindow::Get(static_cast<aura::Window*>(event_handler));
 }
 
 gfx::Point RootWindowController::GetLastMouseLocationInRoot() {
   return window_tree_host_->dispatcher()->GetLastMouseLocationInRoot();
 }
 
 aura::Window* RootWindowController::GetContainer(int container_id) {
   return GetRootWindow()->GetChildById(container_id);
@@ skipping 653 matching lines @@
     EnableTouchHudProjection();
   else
     DisableTouchHudProjection();
 }
 
 RootWindowController* GetRootWindowController(const aura::Window* root_window) {
   return root_window ? GetRootWindowSettings(root_window)->controller : nullptr;
 }
 
 }  // namespace ash