Move QuicClock to quic/platform/

net/tools/quic/quic_epoll_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_TOOLS_QUIC_QUIC_EPOLL_CLOCK_H_
-#define NET_TOOLS_QUIC_QUIC_EPOLL_CLOCK_H_
-
-#include "base/compiler_specific.h"
-#include "base/macros.h"
-#include "net/quic/core/quic_clock.h"
-#include "net/quic/core/quic_time.h"
-
-namespace net {
-
-class EpollServer;
-
-
-// Clock to efficiently retrieve an approximately accurate time from an
-// EpollServer.
-class QuicEpollClock : public QuicClock {
- public:
-  explicit QuicEpollClock(EpollServer* epoll_server);
-  ~QuicEpollClock() override;
-
-  // Returns the approximate current time as a QuicTime object.
-  QuicTime ApproximateNow() const override;
-
-  // Returns the current time as a QuicTime object.
-  // Note: this uses significant resources, please use only if needed.
-  QuicTime Now() const override;
-
-  // Returns the current time as a QuicWallTime object.
-  // Note: this uses significant resources, please use only if needed.
-  QuicWallTime WallNow() const override;
-
-  // Override to do less work in this implementation.  The epoll clock is
-  // already based on system (unix epoch) time, no conversion required.
-  QuicTime ConvertWallTimeToQuicTime(
-      const QuicWallTime& walltime) const override;
-
- protected:
-  EpollServer* epoll_server_;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(QuicEpollClock);
-};
-
-}  // namespace net
-
-#endif  // NET_TOOLS_QUIC_QUIC_EPOLL_CLOCK_H_