Cleanup: IWYU for base/gtest_prod_util.h.

ash/touch/touch_transformer_controller.h

 // Copyright 2014 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.
 
 #ifndef ASH_TOUCH_TOUCH_TRANSFORMER_CONTROLLER_H_
 #define ASH_TOUCH_TOUCH_TRANSFORMER_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/display/window_tree_host_manager.h"
+#include "base/gtest_prod_util.h"
 #include "ui/gfx/transform.h"
 
 namespace ui {
 struct TouchscreenDevice;
 }  // namespace ui
 
 namespace ash {
 
 // TouchTransformerController listens to display configuration change
 // and updates the touch transformation for touch displays.
@@ skipping 55 matching lines @@
   void UpdateTouchTransform(int64_t target_display_id,
                             const DisplayInfo& touch_display,
                             const DisplayInfo& target_display) const;
 
   DISALLOW_COPY_AND_ASSIGN(TouchTransformerController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_TOUCH_TOUCH_TRANSFORMER_CONTROLLER_H_