make SetReceiveBufferSize and SetSendBufferSize return net error codes (instead of bools)

net/udp/udp_socket_libevent.h

Index: net/udp/udp_socket_libevent.h
diff --git a/net/udp/udp_socket_libevent.h b/net/udp/udp_socket_libevent.h
index 130dcaf60d6fae1f5f05ad6a1d16be87eddab1d9..8ec5c212c094cca3a670c7117ac1040c839454df 100644
--- a/net/udp/udp_socket_libevent.h
+++ b/net/udp/udp_socket_libevent.h
@@ -94,10 +94,10 @@ class NET_EXPORT UDPSocketLibevent : public base::NonThreadSafe {
              const CompletionCallback& callback);
 
   // Set the receive buffer size (in bytes) for the socket.
-  bool SetReceiveBufferSize(int32 size);
+  int SetReceiveBufferSize(int32 size);
 
   // Set the send buffer size (in bytes) for the socket.
-  bool SetSendBufferSize(int32 size);
+  int SetSendBufferSize(int32 size);
 
   // Returns true if the socket is already connected or bound.
   bool is_connected() const { return socket_ != kInvalidSocket; }