Land Recent QUIC changes.

net/quic/quic_time.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.
 //
 // QuicTime represents one point in time, stored in microsecond resolution.
 // QuicTime is monotonically increasing, even across system clock adjustments.
 // The epoch (time 0) of QuicTime is unspecified.
 //
 // This implementation wraps the classes base::TimeTicks and base::TimeDelta.
 
@@ skipping 90 matching lines @@
 
 // A QuicWallTime represents an absolute time that is globally consistent. It
 // provides, at most, one second granularity and, in practice, clock-skew means
 // that you shouldn't even depend on that.
 class NET_EXPORT_PRIVATE QuicWallTime {
  public:
   // FromUNIXSeconds constructs a QuicWallTime from a count of the seconds
   // since the UNIX epoch.
   static QuicWallTime FromUNIXSeconds(uint64 seconds);
 
+  // Zero returns a QuicWallTime set to zero. IsZero will return true for this
+  // value.
+  static QuicWallTime Zero();
+
   // ToUNIXSeconds converts a QuicWallTime into a count of seconds since the
   // UNIX epoch.
   uint64 ToUNIXSeconds() const;
 
   bool IsAfter(QuicWallTime other) const;
   bool IsBefore(QuicWallTime other) const;
 
+  // IsZero returns true if this object is the result of calling |Zero|.
+  bool IsZero() const;
+
   // AbsoluteDifference returns the absolute value of the time difference
   // between |this| and |other|.
   QuicTime::Delta AbsoluteDifference(QuicWallTime other) const;
 
   // Add returns a new QuicWallTime that represents the time of |this| plus
   // |delta|.
   QuicWallTime Add(QuicTime::Delta delta) const;
 
   // Subtract returns a new QuicWallTime that represents the time of |this|
   // minus |delta|.
@@ skipping 40 matching lines @@
 inline bool operator<=(QuicTime lhs, QuicTime rhs) {
   return !(rhs < lhs);
 }
 inline bool operator>=(QuicTime lhs, QuicTime rhs) {
   return !(lhs < rhs);
 }
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_TIME_H_