Revert of Moving coordinate conversion methods from ash/wm to ui/wm.

ash/wm/coordinate_conversion.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/wm/coordinate_conversion.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/shell.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/gfx/display.h"
@@ skipping 13 matching lines @@
   return Shell::GetInstance()->display_controller()->
       GetRootWindowForDisplayId(display.id());
 }
 
 aura::Window* GetRootWindowMatching(const gfx::Rect& rect) {
   const gfx::Display& display = Shell::GetScreen()->GetDisplayMatching(rect);
   return Shell::GetInstance()->display_controller()->
       GetRootWindowForDisplayId(display.id());
 }
 
+void ConvertPointToScreen(const aura::Window* window, gfx::Point* point) {
+  CHECK(aura::client::GetScreenPositionClient(window->GetRootWindow()));
+  aura::client::GetScreenPositionClient(window->GetRootWindow())->
+      ConvertPointToScreen(window, point);
+}
+
+void ConvertPointFromScreen(const aura::Window* window,
+                            gfx::Point* point_in_screen) {
+  aura::client::GetScreenPositionClient(window->GetRootWindow())->
+      ConvertPointFromScreen(window, point_in_screen);
+}
+
 }  // namespace wm
 }  // namespace ash