Clean up NPN/ALPN-related SSLClientSocket bits.

net/socket/ssl_client_socket_openssl.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_SOCKET_SSL_CLIENT_SOCKET_OPENSSL_H_
 #define NET_SOCKET_SSL_CLIENT_SOCKET_OPENSSL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 43 matching lines @@
                          const SSLClientSocketContext& context);
   ~SSLClientSocketOpenSSL() override;
 
   const HostPortPair& host_and_port() const { return host_and_port_; }
   const std::string& ssl_session_cache_shard() const {
     return ssl_session_cache_shard_;
   }
 
   // SSLClientSocket implementation.
   void GetSSLCertRequestInfo(SSLCertRequestInfo* cert_request_info) override;
-  NextProtoStatus GetNextProto(std::string* proto) override;
+  NextProtoStatus GetNextProto(std::string* proto) const override;
   ChannelIDService* GetChannelIDService() const override;
 
   // SSLSocket implementation.
   int ExportKeyingMaterial(const base::StringPiece& label,
                            bool has_context,
                            const base::StringPiece& context,
                            unsigned char* out,
                            unsigned int outlen) override;
   int GetTLSUniqueChannelBinding(std::string* out) override;
 
@@ skipping 233 matching lines @@
   // pinning failure. It is a (somewhat) human-readable string.
   std::string pinning_failure_log_;
 
   BoundNetLog net_log_;
   base::WeakPtrFactory<SSLClientSocketOpenSSL> weak_factory_;
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_SSL_CLIENT_SOCKET_OPENSSL_H_