Allow QuicClient to set connection MTU before the handshake is sent.

net/tools/quic/quic_client.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 toy client, which connects to a specified port and sends QUIC
 // request to that endpoint.
 
 #ifndef NET_TOOLS_QUIC_QUIC_CLIENT_H_
 #define NET_TOOLS_QUIC_QUIC_CLIENT_H_
 
@@ skipping 183 matching lines @@
   }
 
   QuicConfig* config() { return &config_; }
 
   void set_store_response(bool val) { store_response_ = val; }
 
   size_t latest_response_code() const;
   const std::string& latest_response_headers() const;
   const std::string& latest_response_body() const;
 
+  // Change the initial maximum packet size of the connection.  Has to be called
+  // before Connect()/StartConnect() in order to have any effect.
+  void set_initial_max_packet_length(QuicByteCount initial_max_packet_length) {
+    initial_max_packet_length_ = initial_max_packet_length;
+  }
+
  protected:
   virtual QuicConnectionId GenerateConnectionId();
   virtual QuicEpollConnectionHelper* CreateQuicConnectionHelper();
   virtual QuicPacketWriter* CreateQuicPacketWriter();
 
   virtual int ReadPacket(char* buffer,
                          int buffer_len,
                          IPEndPoint* server_address,
                          IPAddressNumber* client_ip);
 
@@ skipping 77 matching lines @@
 
   // If true, store the latest response code, headers, and body.
   bool store_response_;
   // HTTP response code from most recent response.
   size_t latest_response_code_;
   // HTTP headers from most recent response.
   std::string latest_response_headers_;
   // Body of most recent response.
   std::string latest_response_body_;
 
+  // The initial value of maximum packet size of the connection.  If set to
+  // zero, the default is used.
+  QuicByteCount initial_max_packet_length_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicClient);
 };
 
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_CLIENT_H_