Revert "chromeos: Move files in //ash/common to //ash, part 3"

ash/scoped_root_window_for_new_windows.cc

Index: ash/scoped_root_window_for_new_windows.cc
diff --git a/ash/scoped_root_window_for_new_windows.cc b/ash/scoped_root_window_for_new_windows.cc
deleted file mode 100644
index 06440b62bc75f591bce7c4048f7e7fd971960e2f..0000000000000000000000000000000000000000
--- a/ash/scoped_root_window_for_new_windows.cc
+++ /dev/null
@@ -1,22 +0,0 @@
-// 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 "ash/scoped_root_window_for_new_windows.h"
-
-#include "ash/wm_shell.h"
-#include "base/logging.h"
-
-namespace ash {
-
-ScopedRootWindowForNewWindows::ScopedRootWindowForNewWindows(
-    WmWindow* new_root) {
-  DCHECK(new_root);
-  WmShell::Get()->scoped_root_window_for_new_windows_ = new_root;
-}
-
-ScopedRootWindowForNewWindows::~ScopedRootWindowForNewWindows() {
-  WmShell::Get()->scoped_root_window_for_new_windows_ = nullptr;
-}
-
-}  // namespace ash