Use a direct include of strings headers in ui/, part 3.

ui/views/corewm/tooltip_controller.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 UI_VIEWS_COREWM_TOOLTIP_CONTROLLER_H_
 #define UI_VIEWS_COREWM_TOOLTIP_CONTROLLER_H_
 
 #include <map>
 
 #include "base/memory/scoped_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/timer.h"
 #include "ui/aura/client/tooltip_client.h"
 #include "ui/aura/window_observer.h"
 #include "ui/base/events/event_handler.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/screen_type_delegate.h"
 #include "ui/views/views_export.h"
 
 namespace aura {
 class Window;
@@ skipping 97 matching lines @@
 
   std::map<aura::Window*, int> tooltip_shown_timeout_map_;
 
   DISALLOW_COPY_AND_ASSIGN(TooltipController);
 };
 
 }  // namespace corewm
 }  // namespace views
 
 #endif  // UI_VIEWS_COREWM_TOOLTIP_CONTROLLER_H_