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

chrome/browser/ui/panels/native_panel_stack_window.h

 // Copyright (c) 2013 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_NATIVE_PANEL_STACK_WINDOW_H_
 #define CHROME_BROWSER_UI_PANELS_NATIVE_PANEL_STACK_WINDOW_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 
 class Panel;
 namespace gfx {
 class Rect;
 class Vector2d;
 }
 
 class NativePanelStackWindowDelegate {
  public:
   // Returns the title representing the whole stack.
@@ skipping 64 matching lines @@
 
   // Draws or clears the attention via system. The system might choose to
   // flash the taskbar icon for attention.
   virtual void DrawSystemAttention(bool draw_attention) = 0;
 
   // Called when the panel is activated.
   virtual void OnPanelActivated(Panel* panel) = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_NATIVE_PANEL_STACK_WINDOW_H_