Rather than passing initial_flow_control_window all the way down the

net/quic/crypto/quic_crypto_client_config.h

 // Copyright 2013 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_QUIC_CRYPTO_QUIC_CRYPTO_CLIENT_CONFIG_H_
 #define NET_QUIC_CRYPTO_QUIC_CRYPTO_CLIENT_CONFIG_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 143 matching lines @@
                                const QuicVersion preferred_version,
                                const CachedState* cached,
                                QuicCryptoNegotiatedParameters* out_params,
                                CryptoHandshakeMessage* out) const;
 
   // FillClientHello sets |out| to be a CHLO message based on the configuration
   // of this object. This object must have cached enough information about
   // the server's hostname in order to perform a handshake. This can be checked
   // with the |IsComplete| member of |CachedState|.
   //
-  // |initial_flow_control_window_bytes| is the size of the initial flow
-  // control window this client will use for new streams.
-  //
   // |now| and |rand| are used to generate the nonce and |out_params| is
   // filled with the results of the handshake that the server is expected to
   // accept. |preferred_version| is the version of the QUIC protocol that this
   // client chose to use initially. This allows the server to detect downgrade
   // attacks.
   //
   // If |channel_id_key| is not null, it is used to sign a secret value derived
   // from the client and server's keys, and the Channel ID public key and the
   // signature are placed in the CETV value of the CHLO.
   QuicErrorCode FillClientHello(const QuicServerId& server_id,
                                 QuicConnectionId connection_id,
                                 const QuicVersion preferred_version,
-                                uint32 initial_flow_control_window_bytes,
                                 const CachedState* cached,
                                 QuicWallTime now,
                                 QuicRandom* rand,
                                 const ChannelIDKey* channel_id_key,
                                 QuicCryptoNegotiatedParameters* out_params,
                                 CryptoHandshakeMessage* out,
                                 std::string* error_details) const;
 
   // ProcessRejection processes a REJ message from a server and updates the
   // cached information about that server. After this, |IsComplete| may return
@@ skipping 97 matching lines @@
 
   // The |user_agent_id_| passed in QUIC's CHLO message.
   std::string user_agent_id_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicCryptoClientConfig);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_QUIC_CRYPTO_CLIENT_CONFIG_H_