Use a direct include of strings headers in rlz/, sandbox/, skia/, sql/, sync/.

sync/engine/syncer_proto_util.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 "sync/engine/syncer_proto_util.h"
 
 #include "base/format_macros.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "google_apis/google_api_keys.h"
 #include "sync/engine/net/server_connection_manager.h"
 #include "sync/engine/syncer.h"
 #include "sync/engine/syncer_types.h"
 #include "sync/engine/throttled_data_type_tracker.h"
 #include "sync/engine/traffic_logger.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/protocol/sync_enums.pb.h"
 #include "sync/protocol/sync_protocol_error.h"
 #include "sync/sessions/sync_session.h"
@@ skipping 606 matching lines @@
 std::string SyncerProtoUtil::ClientToServerResponseDebugString(
     const ClientToServerResponse& response) {
   // Add more handlers as needed.
   std::string output;
   if (response.has_get_updates())
     output.append(GetUpdatesResponseString(response.get_updates()));
   return output;
 }
 
 }  // namespace syncer