Use overloaded operators with QuicTime for addition, subtraction and scalar

net/quic/quic_connection_logger.cc

 // Copyright (c) 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.
 
 #include "net/quic/quic_connection_logger.h"
 
 #include <algorithm>
 #include <limits>
 #include <memory>
 #include <utility>
@@ skipping 445 matching lines @@
     net_log_.AddEvent(
         NetLog::TYPE_QUIC_SESSION_PACKET_RETRANSMITTED,
         base::Bind(&NetLogQuicPacketRetransmittedCallback,
                    original_packet_number, serialized_packet.packet_number));
   }
   // Record time duration from last packet sent to the new packet sent.
   if (last_packet_sent_time_.IsInitialized()) {
     UMA_HISTOGRAM_CUSTOM_TIMES(
         "Net.QuicTimeBetweenTwoPacketSent",
         base::TimeDelta::FromMilliseconds(
-            sent_time.Subtract(last_packet_sent_time_).ToMilliseconds()),
+            (sent_time - last_packet_sent_time_).ToMilliseconds()),
         base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(10),
         100);
   }
   last_packet_sent_time_ = sent_time;
 }
 
 void QuicConnectionLogger::OnPacketReceived(const IPEndPoint& self_address,
                                             const IPEndPoint& peer_address,
                                             const QuicEncryptedPacket& packet) {
   if (local_address_from_self_.GetFamily() == ADDRESS_FAMILY_UNSPECIFIED) {
@@ skipping 412 matching lines @@
       continue;
     }
     // Record some overlapping patterns, to get a better picture, since this is
     // not very expensive.
     if (i % 3 == 0)
       six_packet_histogram->Add(recent_6_mask);
   }
 }
 
 }  // namespace net