Remove default constructors for QuicTime and QuicTime::Delta and used static Zero() methods instead…

net/quic/congestion_control/tcp_cubic_sender.cc

Index: net/quic/congestion_control/tcp_cubic_sender.cc
diff --git a/net/quic/congestion_control/tcp_cubic_sender.cc b/net/quic/congestion_control/tcp_cubic_sender.cc
index 7aab66cf33ba1a4e415908b38c67e1a704fce105..fce3bb9808a8abe61a4a19080251900be9a9bb09 100644
--- a/net/quic/congestion_control/tcp_cubic_sender.cc
+++ b/net/quic/congestion_control/tcp_cubic_sender.cc
@@ -30,7 +30,7 @@ TcpCubicSender::TcpCubicSender(const QuicClock* clock, bool reno)
       end_sequence_number_(0),
       congestion_window_(kInitialCongestionWindow),
       slowstart_threshold_(kMaxCongestionWindow),
-      delay_min_() {
+      delay_min_(QuicTime::Delta::Zero()) {
 }
 
 void TcpCubicSender::OnIncomingQuicCongestionFeedbackFrame(
@@ -97,12 +97,12 @@ void TcpCubicSender::SentPacket(QuicPacketSequenceNumber sequence_number,
 QuicTime::Delta TcpCubicSender::TimeUntilSend(bool retransmit) {
   if (retransmit) {
     // For TCP we can always send a retransmit immediately.
-    return QuicTime::Delta();
+    return QuicTime::Delta::Zero();
   }
   if (AvailableCongestionWindow() == 0) {
     return QuicTime::Delta::Infinite();
   }
-  return QuicTime::Delta();
+  return QuicTime::Delta::Zero();
 }
 
 size_t TcpCubicSender::AvailableCongestionWindow() {
@@ -126,7 +126,7 @@ int TcpCubicSender::BandwidthEstimate() {
 }
 
 void TcpCubicSender::Reset() {
-  delay_min_ = QuicTime::Delta();  // Reset to 0.
+  delay_min_ = QuicTime::Delta::Zero();
   hybrid_slow_start_.Restart();
 }