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

chrome/browser/autocomplete/keyword_provider.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/keyword_provider.h"
 
 #include <algorithm>
 #include <vector>
 
-#include "base/string16.h"
-#include "base/string_util.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/autocomplete/autocomplete_provider_listener.h"
 #include "chrome/browser/extensions/api/omnibox/omnibox_api.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search_engines/template_url.h"
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
@@ skipping 607 matching lines @@
 }
 
 void KeywordProvider::MaybeEndExtensionKeywordMode() {
   if (!current_keyword_extension_id_.empty()) {
     extensions::ExtensionOmniboxEventRouter::OnInputCancelled(
         profile_, current_keyword_extension_id_);
 
     current_keyword_extension_id_.clear();
   }
 }