net: Update the include paths of base/string_piece.h to its new location.

net/quic/quic_data_writer.h

 // 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.
 
 #ifndef NET_QUIC_QUIC_DATA_WRITER_H_
 #define NET_QUIC_QUIC_DATA_WRITER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/port.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "net/base/int128.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_protocol.h"
 
 namespace net {
 
 // This class provides facilities for packing QUIC data.
 //
 // The QuicDataWriter supports appending primitive values (int, string, etc)
 // to a frame instance.  The QuicDataWriter grows its internal memory buffer
@@ skipping 45 matching lines @@
   char* BeginWrite(size_t length);
 
   char* buffer_;
   size_t capacity_;  // Allocation size of payload (or -1 if buffer is const).
   size_t length_;    // Current length of the buffer.
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_DATA_WRITER_H_