Use a direct include of strings headers in chrome/browser/i*/.

chrome/browser/importer/importer_bridge.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_IMPORTER_IMPORTER_BRIDGE_H_
 #define CHROME_BROWSER_IMPORTER_IMPORTER_BRIDGE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "build/build_config.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/importer/importer_data_types.h"
 
 class GURL;
 struct IE7PasswordInfo;
 struct ImportedBookmarkEntry;
 struct ImportedFaviconUsage;
 class TemplateURL;
 // TODO: remove this, see friend declaration in ImporterBridge.
@@ skipping 56 matching lines @@
   // connection, but as an interim step we allow Toolbar5Import to break
   // the abstraction here and assume import is in-process.
   friend class Toolbar5Importer;
 
   virtual ~ImporterBridge();
 
   DISALLOW_COPY_AND_ASSIGN(ImporterBridge);
 };
 
 #endif  // CHROME_BROWSER_IMPORTER_IMPORTER_BRIDGE_H_