Build sync engine as part of the browser build

chrome/browser/sync/util/highres_timer-linux.h

-// Copyright (c) 2009 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.
-//
-// High resolution timer functions for use in Linux.
-
-#ifndef CHROME_BROWSER_SYNC_UTIL_HIGHRES_TIMER_LINUX_H_
-#define CHROME_BROWSER_SYNC_UTIL_HIGHRES_TIMER_LINUX_H_
-
-#include "base/basictypes.h"
-
-#include <sys/time.h>
-
-const uint64 MICROS_IN_SECOND = 1000000L;
-
-// A handy class for reliably measuring wall-clock time with decent resolution.
-//
-// We want to measure time with high resolution on Linux. What to do?
-//
-// RDTSC? Sure, but how do you convert it to wall clock time?
-// clock_gettime? It's not in all Linuxes.
-//
-// Let's just use gettimeofday; it's good to the microsecond.
-class HighresTimer {
- public:
-  // Captures the current start time.
-  HighresTimer();
-
-  // Captures the current tick, can be used to reset a timer for reuse.
-  void Start();
-
-  // Returns the elapsed ticks with full resolution.
-  uint64 GetElapsedTicks() const;
-
-  // Returns the elapsed time in milliseconds, rounded to the nearest
-  // millisecond.
-  uint64 GetElapsedMs() const;
-
-  // Returns the elapsed time in seconds, rounded to the nearest second.
-  uint64 GetElapsedSec() const;
-
-  uint64 start_ticks() const { return start_ticks_; }
-
-  // Returns timer frequency from cache, should be less overhead than
-  // ::QueryPerformanceFrequency.
-  static uint64 GetTimerFrequency();
-  // Returns current ticks.
-  static uint64 GetCurrentTicks();
-
- private:
-  // Captured start time.
-  uint64 start_ticks_;
-};
-
-inline HighresTimer::HighresTimer() {
-  Start();
-}
-
-inline void HighresTimer::Start() {
-  start_ticks_ = GetCurrentTicks();
-}
-
-inline uint64 HighresTimer::GetTimerFrequency() {
-  // Fixed; one "tick" is one microsecond.
-  return MICROS_IN_SECOND;
-}
-
-inline uint64 HighresTimer::GetCurrentTicks() {
-  timeval tv;
-  gettimeofday(&tv, 0);
-
-  return tv.tv_sec * MICROS_IN_SECOND + tv.tv_usec;
-}
-
-inline uint64 HighresTimer::GetElapsedTicks() const {
-  return start_ticks_ - GetCurrentTicks();
-}
-
-#endif  // CHROME_BROWSER_SYNC_UTIL_HIGHRES_TIMER_LINUX_H_