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

sync/syncable/directory_backing_store_unittest.cc

 // Copyright 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 "testing/gtest/include/gtest/gtest.h"
 
 #include <string>
 
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
-#include "base/string_number_conversions.h"
+#include "base/strings/string_number_conversions.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/node_ordinal.h"
 #include "sync/protocol/bookmark_specifics.pb.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/syncable/directory_backing_store.h"
 #include "sync/syncable/on_disk_directory_backing_store.h"
 #include "sync/syncable/syncable-inl.h"
 #include "sync/test/test_directory_backing_store.h"
@@ skipping 3468 matching lines @@
   const std::string& guid2 = TestDirectoryBackingStore::GenerateCacheGUID();
   EXPECT_EQ(24U, guid1.size());
   EXPECT_EQ(24U, guid2.size());
   // In theory this test can fail, but it won't before the universe
   // dies of heat death.
   EXPECT_NE(guid1, guid2);
 }
 
 }  // namespace syncable
 }  // namespace syncer