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

chrome/browser/importer/toolbar_importer.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.
 
 // The functionality provided here allows the user to import their bookmarks
 // (favorites) from Google Toolbar.
 
 #ifndef CHROME_BROWSER_IMPORTER_TOOLBAR_IMPORTER_H_
 #define CHROME_BROWSER_IMPORTER_TOOLBAR_IMPORTER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "chrome/browser/importer/importer.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 
 struct ImportedBookmarkEntry;
 class ImporterBridge;
 class XmlReader;
 
 namespace net {
 class URLFetcher;
@@ skipping 132 matching lines @@
   net::URLFetcher* token_fetcher_;
   net::URLFetcher* data_fetcher_;
 
   // Used to get correct login data for the toolbar server.
   scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
 
   DISALLOW_COPY_AND_ASSIGN(Toolbar5Importer);
 };
 
 #endif  // CHROME_BROWSER_IMPORTER_TOOLBAR_IMPORTER_H_