Use a direct include of strings headers in chrome/browser/ui/b*-p*/.

chrome/browser/ui/panels/panel.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 CHROME_BROWSER_UI_PANELS_PANEL_H_
 #define CHROME_BROWSER_UI_PANELS_PANEL_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "chrome/browser/command_updater.h"
 #include "chrome/browser/command_updater_delegate.h"
 #include "chrome/browser/sessions/session_id.h"
 #include "chrome/browser/ui/panels/panel_constants.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ui/base/base_window.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/rect.h"
 
@@ skipping 372 matching lines @@
 
   // Icon showed in the task bar.
   gfx::Image app_icon_;
 
   base::WeakPtrFactory<Panel> image_loader_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Panel);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_PANEL_H_