Add a new histogram Net.QuicSession.HandshakeConfirmedTime which tracks

net/quic/quic_client_session.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.
 //
 // A client specific QuicSession subclass.  This class owns the underlying
 // QuicConnection and QuicConnectionHelper objects.  The connection stores
 // a non-owning pointer to the helper so this session needs to ensure that
 // the helper outlives the connection.
 
 #ifndef NET_QUIC_QUIC_CLIENT_SESSION_H_
 #define NET_QUIC_QUIC_CLIENT_SESSION_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
 #include "net/base/completion_callback.h"
 #include "net/proxy/proxy_server.h"
 #include "net/quic/quic_client_session_base.h"
 #include "net/quic/quic_connection_logger.h"
 #include "net/quic/quic_crypto_client_stream.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_reliable_client_stream.h"
 
 namespace net {
 
@@ skipping 200 matching lines @@
   scoped_refptr<IOBufferWithSize> read_buffer_;
   scoped_ptr<QuicServerInfo> server_info_;
   scoped_ptr<CertVerifyResult> cert_verify_result_;
   ObserverSet observers_;
   StreamRequestQueue stream_requests_;
   bool read_pending_;
   CompletionCallback callback_;
   size_t num_total_streams_;
   base::TaskRunner* task_runner_;
   BoundNetLog net_log_;
+  base::TimeTicks handshake_start_;  // Time the handshake was started.
   QuicConnectionLogger logger_;
   // Number of packets read in the current read loop.
   size_t num_packets_read_;
   // True when the session is going away, and streams may no longer be created
   // on this session. Existing stream will continue to be processed.
   bool going_away_;
   base::WeakPtrFactory<QuicClientSession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicClientSession);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CLIENT_SESSION_H_