ash: Add RootWindowHostFactory class.

ash/root_window_delegate.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.
+
+#ifndef ASH_ROOT_WINDOW_DELEGATE_H_
+#define ASH_ROOT_WINDOW_DELEGATE_H_
+
+#include "ash/ash_export.h"
+#include "ui/aura/root_window_delegate.h"
+
+namespace ash {
+
+// Implementation of aura::RootWindowDelegate.
+class ASH_EXPORT RootWindowDelegate : public aura::RootWindowDelegate {
+ public:
+  virtual ~RootWindowDelegate() {}
+
+  // Creates a new aura::RootWindowDelegate. The caller owns the returned
+  // value.
+  static aura::RootWindowDelegate* Create();
+
+ protected:
+  RootWindowDelegate() {}
+};
+
+}  // namespace ash
+
+#endif  // ASH_ROOT_WINDOW_DELEGATE_H_