Use a direct include of strings headers in content/browser/, part 1.

content/browser/indexed_db/indexed_db_leveldb_coding.h

 // Copyright (c) 2013 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.
 
 #ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_LEVELDB_CODING_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_LEVELDB_CODING_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/strings/string_piece.h"
 #include "content/common/indexed_db/indexed_db_key.h"
 #include "content/common/indexed_db/indexed_db_key_path.h"
 
 namespace content {
 
 class LevelDBSlice;
 
 CONTENT_EXPORT extern const unsigned char kMinimumIndexId;
 
@@ skipping 421 matching lines @@
   std::vector<char> encoded_user_key_;
   std::vector<char> encoded_primary_key_;
   int64 sequence_number_;
 
   DISALLOW_COPY_AND_ASSIGN(IndexDataKey);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_LEVELDB_CODING_H_