MockClock needs to mock the NowAsDeltaSinceUnixEpoch method.

net/quic/test_tools/mock_clock.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.
 
 #ifndef NET_QUIC_TEST_TOOLS_MOCK_CLOCK_H_
 #define NET_QUIC_TEST_TOOLS_MOCK_CLOCK_H_
 
 #include "net/quic/quic_clock.h"
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/time.h"
 
 namespace net {
 
 class MockClock : public QuicClock {
  public:
   MockClock();
 
   virtual ~MockClock();
 
   void AdvanceTime(QuicTime::Delta delta);
 
   virtual QuicTime Now() const OVERRIDE;
 
+  virtual QuicTime::Delta NowAsDeltaSinceUnixEpoch() const OVERRIDE;
+
   base::TimeTicks NowInTicks() const;
 
-  void AdvanceTime(QuicTime delta);
-
  private:
   QuicTime now_;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_TEST_TOOLS_MOCK_CLOCK_H_