Remove redundant mapping of net errors to strings.

device/bluetooth/bluetooth_socket_win.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 "device/bluetooth/bluetooth_socket_win.h"
 
 #include <objbase.h>
 
 #include <string>
 
@@ skipping 203 matching lines @@
     closesocket(socket_fd);
     return;
   }
 
   // Note: We don't have a meaningful |IPEndPoint|, but that is ok since the
   // TCPSocket implementation does not actually require one.
   int net_result =
       scoped_socket->AdoptConnectedSocket(socket_fd, net::IPEndPoint());
   if (net_result != net::OK) {
     error_callback.Run("Error connecting to socket: " +
-                       std::string(net::ErrorToString(net_result)));
+                       net::ErrorToString(net_result));
     closesocket(socket_fd);
     return;
   }
 
   SetTCPSocket(scoped_socket.Pass());
   success_callback.Run();
 }
 
 void BluetoothSocketWin::DoListen(
     const BluetoothUUID& uuid,
@@ skipping 152 matching lines @@
     return;
   }
 
   scoped_refptr<BluetoothSocketWin> peer_socket =
       CreateBluetoothSocket(ui_task_runner(), socket_thread());
   peer_socket->SetTCPSocket(accept_socket.Pass());
   success_callback.Run(peer_device, peer_socket);
 }
 
 }  // namespace device