Use a direct include of strings headers in chrome/browser/ui/cocoa/.

chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.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_COCOA_OMNIBOX_OMNIBOX_VIEW_MAC_H_
 #define CHROME_BROWSER_UI_COCOA_OMNIBOX_OMNIBOX_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/memory/scoped_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "chrome/browser/ui/cocoa/location_bar/autocomplete_text_field.h"
 #include "chrome/browser/ui/omnibox/omnibox_view.h"
 
 class OmniboxPopupView;
 
 namespace ui {
 class Clipboard;
 }
 
 // Implements OmniboxView on an AutocompleteTextField.
@@ skipping 155 matching lines @@
 
   // Was the delete key pressed with an empty selection at the end of the edit?
   bool delete_at_end_pressed_;
 
   string16 suggest_text_;
 
   DISALLOW_COPY_AND_ASSIGN(OmniboxViewMac);
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_OMNIBOX_OMNIBOX_VIEW_MAC_H_