Correctly restore the auto managed window to the original bounds when becoming single window

ash/wm/workspace/auto_window_management.h

 // 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 "ui/aura/window.h"
+#include "ash/ash_export.h"
+
+namespace gfx {
+class Rect;
+}
+namespace aura {
+class RootWindow;
+class Window;
+}
 
 namespace ash {
 namespace internal {
 
 // Check if after removal or hide of the given |removed_window| an automated
 // desktop location management can be performed and rearrange accordingly.
 void RearrangeVisibleWindowOnHideOrRemove(const aura::Window* removed_window);
 
 // Check if after insertion or showing of the given |added_window| an automated
 // desktop location management can be performed and rearrange accordingly.
 void RearrangeVisibleWindowOnShow(aura::Window* added_window);
 
 } // namespace internal
+
+// Returns the top window used for automated windows location
+// management.
+// TODO(oshima): This is temporarily made public and exported until we
+// move the initial bounds logic in window_sizer_ash.cc into ash.
+ASH_EXPORT aura::Window* GetTopWindowForNewWindow(
+    const aura::RootWindow* root_window);
+
 } // namespace ash
-