[merge to m60] cros: Do not cache |root_window| in ScreenRotationAnimator.

ash/test/display_configuration_controller_test_api.cc

 // Copyright 2017 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/test/display_configuration_controller_test_api.h"
 
 #include "ash/display/display_configuration_controller.h"
 
 namespace ash {
 namespace test {
 
 DisplayConfigurationControllerTestApi::DisplayConfigurationControllerTestApi(
     DisplayConfigurationController* controller)
     : controller_(controller) {}
 
 void DisplayConfigurationControllerTestApi::DisableDisplayAnimator() {
   controller_->ResetAnimatorForTest();
 }
 
-int DisplayConfigurationControllerTestApi::
-    DisplayScreenRotationAnimatorMapSize() {
-  return controller_->rotation_animator_map_.size();
-}
-
 ScreenRotationAnimator*
 DisplayConfigurationControllerTestApi::GetScreenRotationAnimatorForDisplay(
     int64_t display_id) {
   return controller_->GetScreenRotationAnimatorForDisplay(display_id);
 }
 
 }  // namespace test
 }  // namespace ash