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

net/socket/socks5_client_socket.h

Index: net/socket/socks5_client_socket.h
diff --git a/net/socket/socks5_client_socket.h b/net/socket/socks5_client_socket.h
index fb09c198a2b8e05022e558f4854089e6e8cf3ef6..09a4f5447391e086f1e83b5cd1fafe6ebe8fc220 100644
--- a/net/socket/socks5_client_socket.h
+++ b/net/socket/socks5_client_socket.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -62,6 +62,7 @@ class NET_EXPORT_PRIVATE SOCKS5ClientSocket : public StreamSocket {
   virtual bool UsingTCPFastOpen() const OVERRIDE;
   virtual int64 NumBytesRead() const OVERRIDE;
   virtual base::TimeDelta GetConnectTimeMicros() const OVERRIDE;
+  virtual NextProto GetNegotiatedProtocol() const OVERRIDE;
 
   // Socket implementation.
   virtual int Read(IOBuffer* buf,