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

content/browser/indexed_db/indexed_db_database_error.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_DATABASE_ERROR_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATABASE_ERROR_H_
 
 #include "base/basictypes.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "third_party/WebKit/public/platform/WebIDBDatabaseError.h"
 
 namespace content {
 
 class IndexedDBDatabaseError {
  public:
   IndexedDBDatabaseError(uint16 code, const char* message)
       : code_(code), message_(ASCIIToUTF16(message)) {}
   IndexedDBDatabaseError(uint16 code, const string16& message)
       : code_(code), message_(message) {}
   explicit IndexedDBDatabaseError(const WebKit::WebIDBDatabaseError& other)
       : code_(other.code()), message_(other.message()) {}
   ~IndexedDBDatabaseError() {}
 
   uint16 code() const { return code_; }
   const string16& message() const { return message_; }
 
  private:
   const uint16 code_;
   const string16 message_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATABASE_ERROR_H_