Add a new GetNegotiatedProtocol method to StreamSocket and implement in all subclasses.

net/socket/stream_socket.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_STREAM_SOCKET_H_
 #define NET_SOCKET_STREAM_SOCKET_H_
 #pragma once
 
 #include "base/time.h"
 #include "net/base/net_log.h"
@@ skipping 69 matching lines @@
   // Returns true if the underlying transport socket is using TCP FastOpen.
   // TCP FastOpen is an experiment with sending data in the TCP SYN packet.
   virtual bool UsingTCPFastOpen() const = 0;
 
   // Returns the number of bytes successfully read from this socket.
   virtual int64 NumBytesRead() const = 0;
 
   // Returns the connection setup time of this socket.
   virtual base::TimeDelta GetConnectTimeMicros() const = 0;
 
+  // Returns the protocol negotiated via NPN for this socket, or
+  // kProtoUnknown will be returned if NPN is not applicable.
+  virtual NextProto GetNegotiatedProtocol() const = 0;
+
  protected:
   // The following class is only used to gather statistics about the history of
   // a socket.  It is only instantiated and used in basic sockets, such as
   // TCPClientSocket* instances.  Other classes that are derived from
   // StreamSocket should forward any potential settings to their underlying
   // transport sockets.
   class UseHistory {
    public:
     UseHistory();
     ~UseHistory();
@@ skipping 26 matching lines @@
     // identify the motivation.
     bool omnibox_speculation_;
     bool subresource_speculation_;
     DISALLOW_COPY_AND_ASSIGN(UseHistory);
   };
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_STREAM_SOCKET_H_