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

chrome/browser/autocomplete/contact_provider_chromeos_unittest.cc

 // 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.
 
 #include "chrome/browser/autocomplete/contact_provider_chromeos.h"
 
 #include <cmath>
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_input.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/autocomplete/autocomplete_provider.h"
 #include "chrome/browser/chromeos/contacts/contact.pb.h"
 #include "chrome/browser/chromeos/contacts/contact_manager_stub.h"
 #include "chrome/browser/chromeos/contacts/contact_test_util.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
@@ skipping 247 matching lines @@
     EXPECT_EQ(exp_contact.contact_id(), match_id)
         << "Expected contact ID " << exp_contact.contact_id()
         << " for match " << i << " but got " << match_id << " instead";
     if (i > 0) {
       EXPECT_LE(matches[i].relevance, previous_relevance)
           << "Match " << i << " has greater relevance than previous match";
     }
     previous_relevance = matches[i].relevance;
   }
 }