Move base::FreeDeleter into its own header.

ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine.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 UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_
 #define UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_
 
 #include <stdint.h>
 #include <xkbcommon/xkbcommon.h>
+
 #include <vector>
 
 #include "base/containers/hash_tables.h"
+#include "base/memory/free_deleter.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/task_runner.h"
 #include "ui/events/keycodes/scoped_xkb.h"
 #include "ui/events/ozone/layout/events_ozone_layout_export.h"
 #include "ui/events/ozone/layout/keyboard_layout_engine.h"
 #include "ui/events/ozone/layout/xkb/xkb_key_code_converter.h"
 
@@ skipping 87 matching lines @@
 
   std::string current_layout_name_;
 
   // Support weak pointers for attach & detach callbacks.
   base::WeakPtrFactory<XkbKeyboardLayoutEngine> weak_ptr_factory_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_OZONE_LAYOUT_XKB_XKB_KEYBOARD_LAYOUT_ENGINE_H_